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61.
Characterization of a Drosophila melanogaster orthologue of muskelin   总被引:8,自引:0,他引:8  
Adams JC 《Gene》2002,300(1-2):69-78
Visual systems of vertebrates exhibit a striking level of diversity, reflecting their adaptive responses to various color environments. The photosensitive molecules, visual pigments, can be synthesized in vitro and their absorption spectra can be determined. Comparing the amino acid sequences and absorption spectra of various visual pigments, we can identify amino acid changes that have modified the absorption spectra of visual pigments. These hypotheses can then be tested using the in vitro assay. This approach has been a powerful tool in elucidating not only the molecular bases of color vision, but the processes of adaptive evolution at the molecular level.  相似文献   
62.
Summary Visual membranes of the crayfish eye either belong to the small, distally placed rhabdomere of retinula cell R8 or are part of the much more voluminous proximal rhabdom, made up of rhabdomeres belonging to cells R1–R7. Under various conditions of environmental stress (e.g., prolonged darkness, elevated temperature, bright light with and without a concomitant rise in temperature, flickering lights) the visual membranes of R8 prove far more resistant to structural damage than those of R1–R7. Membrane damage is known to occur when dormant lipoxygenases become activated, for example through heat. Since R8 is the only type of visual cell in the crayfish retina that does not contain grains of screening pigment, the view that screening-pigment granules could aggravate or even trigger membrane damage in times of stress is strengthened. Functionally, R8's strong resistance to physical damage when exposed to flickering lights points to a role of the distal rhabdom in the movement detection system of the crayfish eye.  相似文献   
63.
目的:探究经皮椎弓根空心螺钉微创椎体间融合治疗腰椎间盘突出的临床效果及安全性。方法:病例来源于我院2009 年12 月~2013 年12 月收治的确诊为腰椎间盘突出症的病患174 例,依据随机数字表法将其均分为观察组与对照组,每组87 例。其 中,观察组施行Quadrant微创通道经皮椎弓根空心螺钉椎间融合术,对照组施行经后入路开放性椎间融合术。评估和比较两组病 患术前和随访结束时的视觉模拟评分系统(VAS)疼痛评分与Oswestry 功能障碍指数(ODI)的变化及术后并发症的发生情况。结 果:观察组治疗前、出院时及随访一年时的VAS 评分与ODI指数与对照组比较差异均不显著(P>0.05)。观察组手术切口长度、术 后住院时间及术中出血量均明显优于对照组(P<0.01),而其手术所需时间明显长于对照组(P<0.01)。对照组患者术后出现20 例神 经根损伤(22.99%),3 例椎间隙感染(3.45%),其并发症总发生率为(26.44%),而观察组患者术后仅出现3 例神经根损伤,发生率为 3.45%,显著低于对照组(P<0.01)。结论:经皮椎弓根空心螺钉微创椎体间融合治疗的临床效果肯定,能减少对病患的创伤,控制术 后并发症的发生,具有较高的临床应用价值。  相似文献   
64.
Fluorescence spectroscopy has become an established tool at the interface of biology, chemistry and physics because of its exquisite sensitivity and recent technical advancements. However, rhodopsin proteins present the fluorescence spectroscopist with a unique set of challenges and opportunities due to the presence of the light-sensitive retinal chromophore. This review briefly summarizes some approaches that have successfully met these challenges and the novel insights they have yielded about rhodopsin structure and function. We start with a brief overview of fluorescence fundamentals and experimental methodologies, followed by more specific discussions of technical challenges rhodopsin proteins present to fluorescence studies. Finally, we end by discussing some of the unique insights that have been gained specifically about visual rhodopsin and its interactions with affiliate proteins through the use of fluorescence spectroscopy. This article is part of a Special Issue entitled: Retinal Proteins — You can teach an old dog new tricks.  相似文献   
65.
Data integration and visualization are crucial to obtain meaningful hypotheses from the diversity of ‘omics’ fields and the large volume of heterogeneous and distributed data sets. In this review we focus on network analysis as a key technique to integrate, visualize and extrapolate relevant information from diverse data. We first describe challenges in integrating different types of data and then focus on systematically exploring network properties to gain insight into network function. We also describe the relationship between network structures and function of elements that form it. Next, we highlight the role of the interactome in connecting data derived from different experiments, and we stress the importance of network analysis to recognize interaction context-specific features. Finally, we present an example integration to demonstrate the value of the network approach in cancer research, and highlight the importance of dynamic data in the specific context of signaling pathways.  相似文献   
66.
摘要 目的:探讨高血压基底节区脑出血(HBGH)患者血清CXC趋化因子配体1(CXCL1)、CXC趋化因子配体10(CXCL10)与神经损伤指标和微创穿刺引流术后预后的关系。方法:选取2020年2月~2023年4月聊城市人民医院东院区收治的行微创穿刺引流术治疗的HBGH患者162例纳入研究组,选取体检健康的志愿者110例纳入对照组。检测对比两组血清CXCL1、CXCL10和神经损伤指标[神经元特异性烯醇化酶(NSE)、胶质纤维酸性蛋白(GFAP)、S100β蛋白]水平。采用Pearson检验分析血清CXCL1、CXCL10与神经损伤指标的相关性。所有患者均随访3个月,根据改良Rankin量表(mRS)评分分为预后良好组和预后不良组。采用多因素Logistic回归模型分析HBGH患者微创穿刺引流术后预后的影响因素。结果:研究组的血清CXCL1、CXCL10水平高于对照组(P<0.05)。研究组的血清NSE、GFAP、S100β蛋白水平高于对照组(P<0.05)。Pearson检验分析结果显示,血清CXCL1、CXCL10与NSE、GFAP、S100β蛋白均呈正相关(P<0.05)。单因素分析结果显示,预后不良与年龄、甘油三酯(TG)、低密度脂蛋白(LDL)、凝血酶原时间(PT)、C反应蛋白(CRP)、血肿破入脑室、血肿体积、术后24 h内血肿清除率、尿激酶冲管次数、术后颅内出血再发、CXCL1、CXCL10有关(P<0.05)。多因素Logistic回归分析结果显示,年龄偏大、LDL偏高、血肿体积偏大、术后24 h内血肿清除率偏低、尿激酶冲管次数偏多、CXCL1偏高、CXCL10偏高是HBGH患者微创穿刺引流术后预后不良的危险因素(P<0.05)。结论:HBGH患者血清CXCL1、CXCL10水平升高可能导致神经损伤和不良预后。年龄、LDL、血肿体积、术后24 h内血肿清除率、尿激酶冲管次数、CXCL1、CXCL10是HBGH患者术后预后不良的危险因素,值得引起重视。  相似文献   
67.
This paper presents a data-flexible indicator framework for analysis of visual landscape character; the VisuLands framework. The theory-based framework encompasses currently used indicators for visual assessment based on four different data sources: land cover data, aerial photographs, landscape photographs and field observations. This paper presents a study applying the VisuLands framework in analysis of landscape change and its effect on visual scale in a landscape in Southeast Sweden. The paper provides a critical assessment of the pros and cons of the approach. It identifies the advantages and disadvantages of using different data sources as well as the applicability and sensitivity of existing indicators in detecting visible landscape change. The results show that while some of the VisuLands indicators are relatively easily applied, others are more complex and demanding in terms of interpretation. The flexibility of the VisuLands framework makes it applicable and user-friendly as it helps meet the requirements and restrictions of the users. The assessment has shown that the different data sources complement each other and that applying indicators using various data sources, when available, will enhance the comprehensiveness of visual landscape assessment. The experience of this study is that the VisuLands framework is a useful tool in landscape analysis, monitoring and planning, which provides a repeatable, systematic and transparent approach with strong links to landscape theory.  相似文献   
68.
Strepsirrhine and haplorhine primates exhibit highly derived features of the visual system that distinguish them from most other mammals. Comparative data link the evolution of these visual specializations to the sequential acquisition of nocturnal visual predation in the primate stem lineage and diurnal visual predation in the anthropoid stem lineage. However, it is unclear to what extent these shifts in primate visual ecology were accompanied by changes in eye size and shape. Here we investigate the evolution of primate eye morphology using a comparative study of a large sample of mammalian eyes. Our analysis shows that primates differ from other mammals in having large eyes relative to body size and that anthropoids exhibit unusually small corneas relative to eye size and body size. The large eyes of basal primates probably evolved to improve visual acuity while maintaining high sensitivity in a nocturnal context. The reduced corneal sizes of anthropoids reflect reductions in the size of the dioptric apparatus as a means of increasing posterior nodal distance to improve visual acuity. These data support the conclusion that the origin of anthropoids was associated with a change in eye shape to improve visual acuity in the context of a diurnal predatory habitus.  相似文献   
69.
Lab-reared sphingid and noctuid moths appear to feed less than wild moths, and often are starved to enhance responsiveness in feeding assays. To measure the impact of larval nutrition on adult feeding, we raised a model sphingid species, Manduca sexta, on control or modified diets (reduced sugar, protein or water, supplemented beta-carotene) or cut tobacco leaves, then conducted feeding assays with artificial flowers. Behaviour was scored and analysed in a double-blind manner. Larval diet affected adult eclosion time, size and fat content, the latter of which was inversely proportional to moth approaches to the floral array in a flight cage. In contrast, behaviours refractory to feeding (sitting, escaping) were associated with sex and barometric pressure, but not with diet or fat content. Frequency of floral approaches and probing was not associated with any variable. However, moths reared on beta-carotene-supplemented diet were 2-3 times more likely to feed, and significantly less likely to sit or show "escape" behaviour than were moths from most other treatments. Our results suggest that decreased visual sensitivity, rather than increased fat content, accounts for reduced adult feeding by lab-reared M. sexta.  相似文献   
70.
Western scrub-jays (Aphelocoma californica) hide food and rely on spatial memory to recover their caches at a later date. They also rely on observational spatial memory to steal caches made by other individuals. Successful pilfering may require an understanding of allocentric space because the observer will often be in a different position from the demonstrator when the caching event occurs. We compared cache recovery accuracy of pairs of observers that watched a demonstrator cache food. The pattern of recovery searches showed that observers were more accurate when they had observed the caching event from the same viewing direction as the demonstrator than when they had watched from the opposite direction. Search accuracy was not affected by whether or not the tray-specific local cues provided left–right landmark information (i.e. heterogeneous vs. homogeneous local cues), or whether or not the caching tray location was rotated. Taken together, these results suggest that observers have excellent spatial memory and that they have little difficulty with mental rotation.  相似文献   
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