99 resultados para FPS


Relevância:

10.00% 10.00%

Publicador:

Resumo:

浒苔(Enteromorpha)是青岛沿海常见的一种绿藻。2008年6月份,在我国黄海海域爆发了一场大面积浒苔“绿潮”。本文研究了青岛沿海产缘管浒苔(QE)和“绿潮”浒苔(GE)的化学组成,并对其多糖的化学组成、结构及生物学活性进行了初步研究,为进一步开发利用浒苔提供实验依据。 对两种浒苔主要化学组成进行了分析,QE除灰分含量明显高于GE的含量外,水分、碳水化合物、粗脂肪和粗蛋白含量均低于GE的。两种浒苔均含有丰富的氨基酸,其中含量最高的是天门冬氨酸和谷氨酸;必需氨基酸含量占总氨基酸含量的42.755%和44.989%。不饱和脂肪酸含量占总脂肪酸含量的34.156%和34.278%。结果表明浒苔是一种矿物质和蛋白含量高,脂肪含量低,必需氨基酸和必需脂肪酸含量高的优质食物资源。 以水提醇沉法制备浒苔多糖,QE和GE多糖分别命名为QEP和GEP,并利用琼脂糖凝胶离子交换色谱对所得多糖进行分级纯化。高效液相色谱测定单糖组成,两种多糖均为鼠李糖-木糖-葡萄糖醛酸聚合物,其中鼠李糖含量占中性糖的67.55%和65.56%,木糖占中性糖的24.61%和19.33%。离子交换色谱分级结果表明,QEP主要由两种组分,分别为鼠李糖-木糖-半乳糖-糖醛酸聚合物和鼠李糖-木糖-糖醛酸聚合物;GEP主要组分为鼠李糖-木糖-甘露糖-糖醛酸聚合物。利用红外光谱、甲基化分析和核磁共振分析多糖QEP的结构,并利用ChemNMR软件辅助分析NMR谱图,结果表明,多糖主要有(1→2,4)-和(1→4)-连接的鼠李糖残基,(1→4)-连接的木糖残基,硫酸根主要连接在鼠李糖基3位。 研究了QEP及其分级组分对超氧阴离子、羟自由基、1,1-二苯基苦基苯肼(DPPH)的清除作用和还原能力,结果表明各组分均具有一定的清除自由基能力,其中QEP各项清除能力均较强,且还原能力最强,具有良好的抗氧化活性。以透明质酸和甘油作为对照,研究了GEP和本实验室褐藻多糖硫酸酯(FPS)及其衍生物的保湿和吸湿能力,结果表明GEP、低分子量FPS,以及低分子量FPS的离子交换凝胶色谱分级产物均有较强的保湿和吸湿活性,且与天然活性保湿因子透明质酸的保湿和吸湿特征很相似。GEP相对透明质酸、低分子量FPS及其衍生物而言,样品制备简单,原材料来源丰富,是良好的保湿活性物质。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

褐藻多糖硫酸酯(Fucoidan Polysaccharide of Sulfated, FPS)是褐藻细胞间的一类硫酸化多糖,组成复杂,在不同褐藻中变化很大,典型的结构是岩藻多糖硫酸酯,也有由甘露糖、半乳糖、糖醛酸、木糖、葡萄糖、褐藻糖等多种单糖组成的结构复杂的杂多糖。研究发现FPS具有抗凝血、降血脂、抗肿瘤和抗HIV的作用,成为当今天然药物主攻的重点之一。由中国科学院海洋研究所所主持研究的海洋新药——褐藻多糖硫酸酯,用于临床治疗肾病综合症和中、早期肾衰具有很好的疗效。本论文研究的注射用褐藻多糖硫酸酯是用过氧化氢-抗坏血酸(1:1)体系降解所得的低分子量FPS,并用琼脂糖凝胶(DEAE)色谱柱进行分级制得,在治疗肾脏疾病方面,具有意想不到的良好效果。 本论文模拟植物生长发育过程中的氧化还原反应,分别用抗坏血酸-过氧化氢和Fe2+-过氧化氢-抗坏血酸两种体系降解FPS。各降解试剂的比例和浓度是影响降解效果的主要因素。分别用抗坏血酸-过氧化氢体系和Fe2+-过氧化氢-抗坏血酸体系降解所得样品的硫酸根、褐藻糖和糖醛酸含量与原料多糖无明显差别,红外光谱与原料多糖一致,表明多糖在降解过程中化学组成和结构并未发生改变。而所得样品多分散指数在1.49-1.77之间,表明用此法能获得分子量分布范围较窄的低分子量多糖。 本论文建立了柱前衍生化高效液相色谱法分析褐藻多糖硫酸酯中的单糖组成,将多糖样品用2 mol•L-1三氟乙酸降解成单糖后,以核糖为内标,用1-苯基-3-甲基-5-吡唑啉酮(PMP)进行柱前衍生化,优化分析条件,采用反相高效液相色谱,245nm紫外检测和使用梯度洗脱,分离测定各单糖。方法学验证实验,在浓度0.10 mmol•L-1~2.0 mmol•L-1各单糖衍生物都有良好的线性关系(r2≥0.999);除葡萄糖醛酸外,各单糖衍生物都有很好的重现性和稳定性;甘露糖、鼠李糖、葡萄糖醛酸、葡萄糖、半乳糖、木糖、褐藻糖平均加样回收率分别为86.2%,95.1%,62.5%,102.0%,94.8%,66.6%,105.1%。此法可以用于FPS中褐藻糖、半乳糖、葡萄糖主要单糖进行含量测定。 本论文对注射用褐藻多糖硫酸酯的理化性质进行研究,包括性状、鉴别、检查和含量测定,同时做了原料药的强制降解实验,为原料药质量标准的制定和制 剂研究提供了依据。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本论文在FPS研究的基础上,结合中医配伍理论,研究将FPS与几味传统中药-大黄、黄芪、泽泻、益母草的提取物组合成治疗慢性肾功能衰竭的海洋复方新药物。由于FPS研究相对成熟,故对复方药物中FPS外其它组分(以下简称复方)的提取、分离工艺以及制定复方质量的标准和检测方法等药学内容进行研究,为下一步新药的开发打下基础。 1. 对复方的醇提与水提进行了比较,确定了复方最佳提取方法-醇提。采用正交实验设计方法对醇提工艺进行优化,以复方中主要有效成分的含量为指标进行综合评价,得到了复方提取的最佳工艺:8倍量95%乙醇回流提取两次,1.5h/次,并对该提取工艺进行了验证实验,结果表明本工艺提取物中各主要有效成分的含量均较高,是可靠可行的。 2. 采用微波水提法,对复方中的单味药-黄芪的主要有效成分黄芪皂苷的提取进行了研究,通过正交实验设计方法优选出了最佳提取工艺为20倍量水、微波功率800 W、对60目黄芪提取两次、15 min/次。将该工艺与传统乙醇回流提取方法进行了对比,结果表明该工艺快速、经济、有较好的皂苷提取率,是黄芪皂苷提取的很好的方法。 3. 进行缺FPS的褐藻糖含量测定阴性对照实验,结果阴性无干扰,褐藻糖含量测定可以作为控制复方质量的一个指标。分别做缺大黄和缺黄芪阴性对照实验,结果总蒽醌和总皂苷含量测定阴性干扰较大,大黄素含量测定阴性无干扰,确定大黄素含量测定为控制复方质量的另一指标。 4. 进行复方提取物质量控制指标之一-大黄素含量测定的分析方法学研究,找到了一稳定可行的方法-HPLC方法,该方法测定条件为:流动相甲醇与0.1%磷酸比例为85:15,柱温40℃,通过ODS柱分离,用二极管阵列检测器在436 nm下测定含量。该方法测定复方提取物中大黄素含量精密度高、专一性好、干扰小,可用来控制复方的质量。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Seismic Numerical Modeling is one of bases of the Exploratory Seismology and Academic Seismology, also is a research field in great demand. Essence of seismic numerical modeling is to assume that structure and parameters of the underground media model are known, simulate the wave-field and calculate the numerical seismic record that should be observed. Seismic numerical modeling is not only a means to know the seismic wave-field in complex inhomogeneous media, but also a test to the application effect by all kinds of methods. There are many seismic numerical modeling methods, each method has its own merits and drawbacks. During the forward modeling, the computation precision and the efficiency are two pivotal questions to evaluate the validity and superiority of the method. The target of my dissertation is to find a new method to possibly improve the computation precision and efficiency, and apply the new forward method to modeling the wave-field in the complex inhomogeneous media. Convolutional Forsyte polynomial differentiator (CFPD) approach developed in this dissertation is robust and efficient, it shares some of the advantages of the high precision of generalized orthogonal polynomial and the high speed of the short operator finite-difference. By adjusting the operator length and optimizing the operator coefficient, the method can involve whole and local information of the wave-field. One of main tasks of the dissertation is to develop a creative, generalized and high precision method. The author introduce convolutional Forsyte polynomial differentiator to calculate the spatial derivative of seismic wave equation, and apply the time staggered grid finite-difference which can better meet the high precision of the convolutional differentiator to substitute the conventional finite-difference to calculate the time derivative of seismic wave equation, then creating a new forward method to modeling the wave-field in complex inhomogeneous media. Comparing with Fourier pseudo-spectral method, Chebyshev pseudo-spectral method, staggered- grid finite difference method and finite element method, convolutional Forsyte polynomial differentiator (CFPD) method has many advantages: 1. Comparing with Fourier pseudo-spectral method. Fourier pseudo-spectral method (FPS) is a local operator, its results have Gibbs effects when the media parameters change, then arose great errors. Therefore, Fourier pseudo-spectral method can not deal with special complex and random heterogeneous media. But convolutional Forsyte polynomial differentiator method can cover global and local information. So for complex inhomogeneous media, CFPD is more efficient. 2. Comparing with staggered-grid high-order finite-difference method, CFPD takes less dots than FD at single wave length, and the number does not increase with the widening of the studying area. 3. Comparing with Chebyshev pseudo-spectral method (CPS). The calculation region of Chebyshev pseudo-spectral method is fixed in , under the condition of unchangeable precision, the augmentation of calculation is unacceptable. Thus Chebyshev pseudo-spectral method is inapplicable to large area. CFPD method is more applicable to large area. 4. Comparing with finite element method (FE), CFPD can use lager grids. The other task of this dissertation is to study 2.5 dimension (2.5D) seismic wave-field. The author reviews the development and present situation of 2.5D problem, expatiates the essentiality of studying the 2.5D problem, apply CFPD method to simulate the seismic wave-field in 2.5D inhomogeneous media. The results indicate that 2.5D numerical modeling is efficient to simulate one of the sections of 3D media, 2.5D calculation is much less time-consuming than 3D calculation, and the wave dispersion of 2.5D modeling is obviously less than that of 3D modeling. Question on applying time staggered-grid convolutional differentiator based on CFPD to modeling 2.5D complex inhomogeneous media was not studied by any geophysicists before, it is a fire-new creation absolutely. The theory and practices prove that the new method can efficiently model the seismic wave-field in complex media. Proposing and developing this new method can provide more choices to study the seismic wave-field modeling, seismic wave migration, seismic inversion, and seismic wave imaging.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Realising high performance image and signal processing
applications on modern FPGA presents a challenging implementation problem due to the large data frames streaming through these systems. Specifically, to meet the high bandwidth and data storage demands of these applications, complex hierarchical memory architectures must be manually specified
at the Register Transfer Level (RTL). Automated approaches which convert high-level operation descriptions, for instance in the form of C programs, to an FPGA architecture, are unable to automatically realise such architectures. This paper
presents a solution to this problem. It presents a compiler to automatically derive such memory architectures from a C program. By transforming the input C program to a unique dataflow modelling dialect, known as Valved Dataflow (VDF), a mapping and synthesis approach developed for this dialect can
be exploited to automatically create high performance image and video processing architectures. Memory intensive C kernels for Motion Estimation (CIF Frames at 30 fps), Matrix Multiplication (128x128 @ 500 iter/sec) and Sobel Edge Detection (720p @ 30 fps), which are unrealisable by current state-of-the-art C-based synthesis tools, are automatically derived from a C description of the algorithm.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose: Patients living with cancer identify family physicians (FPs; ie, primary care physicians) as a preferred resource for supportive cancer care (SCC), either through direct provision or referral. However, little research exists on the specific role FPs play in addressing these needs. Methods: A mailed survey was sent to all FPs in a health care region in Ontario, Canada, to determine their current and preferred roles in the specific provision of SCC to patients with cancer who have been newly diagnosed or are at the end of life. Results: Completed surveys were received from 84 (64%) of 183 eligible FPs. Most practitioners reported providing for their patients' various SCC needs. However, clear gaps were demonstrated in psychosocial and nutritional counseling and in providing information about SCC services. FPs were satisfied with their current role reported in SCC coordination, although the type of role varied; FPs who were asked about their end-of-life patients tended to see themselves as part of coordinating teams, whereas FPs asked about their recently diagnosed patients were more likely to defer this responsibly to a third party. Conclusion: This study identified gaps in the provision of psychosocial and informational care to patients with cancer that may result in unmet needs. In general, FPs do not see themselves as primarily responsible for coordinating patients' SCC and do not wish to assume this role. Accordingly, models that involve FPs as team members in SCC coordination are more feasible for reducing patient need. Copyright © 2010 by American Society of Clinical Oncology.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

There is demand for an easily programmable, high performance image processing platform based on FPGAs. In previous work, a novel, high performance processor - IPPro was developed and a Histogram of Orientated Gradients (HOG) algorithm study undertaken on a Xilinx Zynq platform. Here, we identify and explore a number of mapping strategies to improve processing efficiency for soft-cores and a number of options for creation of a division coprocessor. This is demonstrated for the revised high definition HOG implementation on a Zynq platform, resulting in a performance of 328 fps which represents a 146% speed improvement over the original realization and a tenfold reduction in energy.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Purpose: Pretargeted radioimmunotherapy (PRIT) using streptavidin (SAv)-biotin technology can deliver higher therapeutic doses of radioactivity to tumors than conventional RIT. However, "endogenous" biotin can interfere with the effectiveness of this approach by blocking binding of radiolabeled biotin to SAv. We engineered a series of SAv FPs that downmodulate the affinity of SAv for biotin, while retaining high avidity for divalent DOTA-bis-biotin to circumvent this problem.Experimental Design: The single-chain variable region gene of the murine 1F5 anti-CD20 antibody was fused to the wild-type (WT) SAv gene and to mutant SAv genes, Y43A-SAv and S45A-SAv. FPs were expressed, purified, and compared in studies using athymic mice bearing Ramos lymphoma xenografts.Results: Biodistribution studies showed delivery of more radioactivity to tumors of mice pretargeted with mutant SAv FPs followed by (111)In-DOTA-bis-biotin [6.2 +/- 1.7% of the injected dose per gram (%ID/gm) of tumor 24 hours after Y43A-SAv FP and 5.6 +/- 2.2%ID/g with S45A-SAv FP] than in mice on normal diets pretargeted with WT-SAv FP (2.5 +/- 1.6%ID/g; P = 0.01). These superior biodistributions translated into superior antitumor efficacy in mice treated with mutant FPs and (90)Y-DOTA-bis-biotin [tumor volumes after 11 days: 237 +/- 66 mm(3) with Y43A-SAv, 543 +/- 320 mm(3) with S45A-SAv, 1129 +/- 322 mm(3) with WT-SAv, and 1435 +/- 212 mm(3) with control FP (P < 0.0001)].Conclusions: Genetically engineered mutant-SAv FPs and bis-biotin reagents provide an attractive alternative to current SAv-biotin PRIT methods in settings where endogenous biotin levels are high. Clin Cancer Res; 17(23); 7373-82. (C)2011 AACR.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Introduction: The prevalence of coronary artery disease (CAD) is ever increasing in western industrialized societies. An individuals overall risk for CAD may be quantified by integrating a number of factors including, but not limited to, cardiorespiratory fitness, body composition, blood lipid profile and blood pressure. It might be expected that interventions aimed at improving any or all of these independent factors might improve an individual 's overall risk. To this end, the influence of standard endurance type exercise on cardiorespiratory fitness, body composition, blood lipids and blood pressure, and by extension the reduction of coronary risk factors, is well documented. On the other hand, interval training (IT) has been shown to provide an extremely powerful stimulus for improving indices of cardiorespiratory function but the influence of this training type on coronary risk factors is unknown. Moreover, the vast majority of studies investigating the effects of IT on fitness have used laboratory type training protocols. As a result of this, the influence of participation in interval-type recreational sports on cardiorespiratory fitness and coronary risk factors is unknown. Aims: The aim of the present study was to evaluate the effectiveness of recreational ball hockey, a sport associated with interval-type activity patterns, on indices of aerobic function and coronary risk factors in sedentary men in the approximate age range of 30 - 60 years. Individual risk factors were compiled into an overall coronary risk factor score using the Framingham Point Scale (FPS). Methods: Twenty-four sedentary males (age range 30 - 60) participated in the study. Subject activity level was assessed apriori using questionnaire responses. All subjects (experimental and control) were assessed to have been inactive and sedentary prior to participation in the study. The experimental group (43 ± 3 years; 90 ± 3 kg) (n = 11) participated in one season of recreational ball hockey (our surrogate for IT). Member of this group played a total of 16 games during an 11 week span. During this time, the control group (43 ± 2 years; 89 ± 2 kg) (n = 11) performed no training and continued with their sedentary lifestyle. Prior to and following the ball hockey season, experimental and control subjects were tested for the following variables: 1) cardiorespiratory fitness (as V02 Max) 2) blood lipid profile 3) body composition 5) waist to hip ratio 6) blood glucose levels and 7) blood pressure. Subject V02 Max was assessed using the Rockport submaximal walking test on an indoor track. To assess body composition we determined body mass ratio (BMI), % body fat, % lean body mass and waist to hip ratio. The blood lipid profile included high density lipoprotein, low density lipoprotein and total cholesterol levels; in addition, the ratio of total cholesterol to high density was calculated. Blood triglycerides were also assessed. All data were analyzed using independent t - tests and all data are expressed as mean ± standard error. Statistical significance was accepted at p :S 0.05. Results: Pre-test values for all variables were similar between the experimental and control group. Moreover, although the intervention used in this study was associated with changes in some variables for subjects in the experimental group, subjects in the control group did not exhibit any changes over the same time period. BODY COMPOSITION: The % body fat of experimental subjects decreased by 4.6 ± 0.5%, from 28.1 ± 2.6 to 26.9 ± 2.5 % while that of the control group was unchanged at 22.7 ± 1.4 and 22.2 ± 1.3 %. However, lean body mass of experimental and control subjects did not change at 64.3 ± 1.3 versus 66.1 ± 1.3 kg and 65.5 ± 0.8 versus 64.7 ± 0.8 kg, respectively. In terms of body mass index and waist to hip ratio, neither the experimental nor the control group showed any significant change. Respective values for the waist to hip ratio and body mass index (pre and post) were as follows: 1 ± 0.1 vs 0.9 ± 0.1 (experimental) and 0.9 ± 0.1 versus 0.9 ± 0.1 (controls) while for BMI they were 29 ± 1.4 versus 29 ± 1.2 (experimental) and 26 ± 0.7 vs. 26 ± 0.7 (controls). CARDIORESPIRATORY FITNESS: In the experimental group, predicted values for absolute V02 Max increased by 10 ± 3% (i.e. 3.3 ± 0.1 to 3.6 ± 0.1 liters min -1 while that of control subjects did not change (3.4 ± 0.2 and 3.4 ± 0.2 liters min-I). In terms of relative values for V02 Max, the experimental group increased by 11 ± 2% (37 ± 1.4 to 41 ± 1.4 ml kg-l min-I) while that of control subjects did not change (41 ± 1.4 and 40 ± 1.4 ml kg-l min-I). BLOOD LIPIDS: Compared to pre-test values, post-test values for HDL were decreased by 14 ± 5 % in the experiment group (from 52.4 ± 4.4 to 45.2 ± 4.3 mg dl-l) while HDL data for the control group was unchanged (49.7 ± 3.6 and 48.3 ± 4.1 mg dl-l, respectively. On the other hand, LDL levels did not change for either the experimental or control group (110.2 ± 10.4 versus 112.3 ± 7.1 mg dl-1 and 106.1 ± 11.3 versus 127 ± 15.1 mg dl-1, respectively). Further, total cholesterol did not change in either the experimental or control group (181.3 ± 8.7 mg dl-1 versus 178.7± 4.9 mg dl-l) and 190.7 ± 12.2 versus 197.1 ± 16.1 mg dl-1, respectively). Similarly, the ratio of TC/HDL did not change for either the experimental or control group (3.8 ± 0.4 versus 4.5 ± 0.5 and 4 ± 0.4 versus 4.2 ± 0.4, respectively). Blood triglyceride levels were also not altered in either the experimental or control group (100.3 ± 19.6 versus 114.8 ± 15.3 mg dl-1 and 140 ± 23.5 versus 137.3 ± 17.9 mg dl-l, respectively). BLOOD GLUCOSE: Fasted blood glucose levels did not change in either the experimental or control group. Pre- and post-values for experimental and control groups were 92.5 ± 4.8 versus 93.3 ± 4.3 mg dl-l and 92.3 ± 11.3 versus 93.2 ± 2.6 mg dl-1 , respectively. BLOOD PRESSURE: No aspect of blood pressure was altered in either the experimental or control group. For example, pre- and post-test systolic blood pressures were 131 ± 2 versus 129 ± 2 mmHg (experimental) and 123 ± 2 and 125 ± 2 mmHg (controls), respectively. Pre- and post-test diastolic blood pressures were 84 ± 2 and 83 ± 2 mmHg (experimental) and 81 ± 1 versus 82 ± 1 mmHg, respectively. Similarly, calculated pulse pressure was not altered in the experimental or control as pre- and post-test values were 47 ± 1 versus 47 ± 2 mmlHg and 42 ± 2 versus 43 ± 2 mmHg, respectively. FRAMINGHAM POINT SCORE: The concerted changes reported above produced an increased risk in the Framingham Point Score for the subjects in the experimental group. For example, the pre- and post-test FPS increased from 1.4 ± 0.9 to 2.7 ± 0.7. On the other hand, pre- and post-test scores for the control group were 1.8 ± 1 versus 1.8 ± 0.9. Conclusions: Our data confirms previous studies showing that interval-type exercise is a useful intervention for increasing aerobic fitness. Moreover, the increase in V02 Max we found in response to limited participation in ball hockey (i.e. 16 games) suggests that recreational sport may help reduce this aspect of coronary risk in previously sedentary individual. On the other hand, our results showing little or no positive change in body composition, blood lipids or blood pressures suggest that one season of recreational sport in not in of itself a powerful enough stimulus to reduce the overall risk of coronary artery disease. In light of this, it is recommended that, in addition to participation in recreational sport, the performance of regular physical activity is used as an adjunct to provide a more powerful overall stimulus for decreasing coronary risk factors. LIMITATIONS: The increase in the FPS we found for the experimental group, indicative of an increased risk for coronary disease, was largely due to the large decrease in HDL we observed after compared to above one season of ball hockey. In light of the fact that cardiorespiratory fitness was increased and % body fat was decreased, as well as the fact that other parameters such as blood pressure showed positive (but non statistically significant) trends, the possibility that the decrease in HDL showed by our data was anomalous should be considered. FUTURE DIRECTIONS: The results of this study suggesting that recreational sport may be a potentially useful intervention in the reduction of CAD require to be corroborated by future studies specifically employing 1) more rigorous assessment of fitness and fitness change and 2) more prolonged or frequent participants.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Une cellule se divise en deux par le processus de cytokinèse. Elle requiert la coordination de plusieurs composants pour éviter la formation des cellules potentiellement cancéreuses. Premièrement, un anneau contractile (AC) dépendant de l’actine et de Rho-GTP diminue le diamètre de la cellule jusqu’à la formation d’une structure plus stable indépendante de l’actine, l’anneau du midbody (AM) qui guide l’éventuelle séparation des cellules sœurs. Diaphanous (Dia) est une formine dépendante de Rho responsable de l’agencement des filaments d’actine non ramifiés qui se localise à l’AC et est essentielle à la cytokinèse. Nous avons étudié le rôle de Dia pendant la cytokinèse par microscopie de haute résolution en temps réel pour suivre le comportement dynamique des protéines fluorescentes (PF) dans des cellules de Drosophile S2. Une construction fonctionnelle de Dia-PF est recrutée à l’AC et l’AM indépendamment de l’actine mais est absente dans l’AM mature. Dia quitte l’AM au même temps où l’AM dévient indépendant d’actine. La déplétion de Dia par ARN interférant ralentit la constriction de l’AC, augmente les oscillations et, dans 70% des cas, les cellules échouent la cytokinèse pendant la constriction, suggérant que Dia a un rôle dans l’organisation de l’AC. LifeAct-PF, une sonde pour F-actine, dévoile une diminution des filaments d’actine spécifique à l’AC des cellules dépourvues de Dia pendant que Anilline-PF et Myosine-PF sont recrutées en puncta. Ces résultats soutiennent un modèle où Dia nuclée des filaments d’actine qui permettent l’organisation dynamique de l’AC et la perte de Dia régule la transition à l’AM stable indépendant d’actine.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Grâce à son accessibilité, sa polyvalence et sa sécurité, l'échocardiographie est devenue la technique d'imagerie la plus utilisée pour évaluer la fonction cardiaque. Au vu du succès de l'échographie ultrarapide par ondes planes des techniques similaires pour augmenter la résolution temporelle en échocardiographie ont été mise en oeuvre. L’augmentation de la résolution temporelle de l’échographie cardiaque au-delà des valeurs actuellement atteignables (~ 60 à 80 images par secondes), pourrait être utilisé pour améliorer d’autres caractéristiques de l'échocardiographie, comme par exemple élargir la plage de vitesses détectables en imagerie Doppler couleur limitées par la valeur de Nyquist. Nous avons étudié l'échocardiographie ultrarapide en utilisant des fronts d’ondes ultrasonores divergentes. La résolution temporelle atteinte par la méthode d'ondes divergentes a permis d’améliorer les capacités des modes d’échocardiographie en mode B et en Doppler couleur. La résolution temporelle de la méthode mode B a été augmentée jusqu'à 633 images par secondes, tout en gardant une qualité d'image comparable à celle de la méthode d’échocardiographie conventionnelle. La vitesse de Nyquist de la méthode Doppler couleur a été multipliée jusqu'à 6 fois au delà de la limite conventionnelle en utilisant une technique inspirée de l’imagerie radar; l’implémentation de cette méthode n’aurait pas été possible sans l’utilisation de fronts d’ondes divergentes. Les performances avantageuses de la méthode d'échocardiographie ultrarapide sont supportées par plusieurs résultats in vitro et in vivo inclus dans ce manuscrit.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

FPS is a more general form of synchronization. Hyperchaotic systems possessing more than one positive Lypaunov exponent exhibit highly complex behaviour and are more suitable for some applications like secure communications. In this thesis we report studies of FPS and MFPS of a few chaotic and hyperchaotic systems. When all the parameters of the system are known we show that active nonlinear control method can be efectively used to obtain FPS. Adaptive nonlinear control and OPCL control method are employed for obtaining FPS and MFPS when some or all parameters of the system are uncertain. A secure communication scheme based on MFPS is also proposed in theory. All our theoretical calculations are verified by numerical simulations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In India, Food Security meant supply of food grains and the medium was Public Distribution System. Public Distribution System (PDS) is a rationing mechanism that entitles households to specified quantities of selected commodities at subsidized prices. The Objectives of PDS are maintaining Price Stability, rationing during times of scarcity, welfare of the poor, and keeping a check on private trade. Kerala has registered remarkable improvement in poverty reduction in general over the years among all social sections, including scheduled caste and scheduled tribe population. As part of the structural adjustment intended to reduce public expenditure, PDS has been modified as Revamped PDS (RPDS) during 1992 and later on as Targeted PDS (TPDS) in 1997, intended to target households on the basis of income criterion, classifying people as Below Poverty Line (BPL) and Above Poverty Line (APL). TPDS provides 25Kg. of food gra.ins through the Fair Price Shops per month @ Rs.3/- per Kg. of rice/ wheat to the BPL category and @Rs.8.90 and Rs.6.7O for rice and wheat respectively to the APL category of people. Since TPDS is intended to target the poor people, the subsidy spent by the government for the scheme should be beneficial to the poor people and naturally they should utilize the benefits by purchasing the food grains allotted under the scheme. Several studies have shown that there is underutilization of the allotments under TPDS. Therefore, the extent of utilization of TPDS in food grains, how and why remains as a major hurdle, in improving the structure and system of PDS. Livelihood of the tribal population being under threat due to increasing degradation of the resources, the targeting system ought to be effective among the tribal population. Therefore, performance of the TPDS in food grains, in terms of the utilization by the tribal population in Kerala, impact thereof and the factors, if any, affecting proper utilization were considered as the research problem in this study. The study concentrated on the pattern of consumption of food grains by the tribal people, whether their hunger needs are met by distribution of food grains through the TPDS, extent to which TPDS in food grains reduce their share of expenditure on food in the total household expenditure, and the factors affecting the utilization of the TPDS in food grains by the tribal population. Going through the literature, it has been noted that only few studies concentrated on the utilization of TPDS in food grains among the tribal population in Kerala.The Research Design used in this study is descriptive in nature, but exploratory in some aspects. Idukki, Palakkad and Wayanad have more than 60% of the population of the tribals in the state. Within the three districts mentioned above, 14 villages with scheduled tribe concentration were selected for the study. 95 tribal colonies were selected from among the various tribal settlements. Collection of primary data was made from 1231 households with in the above tribal colonies. Analysis of data on the socio-economic factors of the tribal people, pattern of food consumption, extent of reduction in the share of expenditure on food among the household expenditure of the tribal people and the impact of TPDS on the tribal families etc. and testing of hypotheses to find out the relation/association of each of the six variables, using the data on BPL and APL categories of households separately have resulted in findings such as six percent of the tribal families do not have Ration Cards, average per capita consumption of food grains by the tribal people utilizing TPDS meets 62% of their minimum requirement, whereas the per capita consumption of food grains by the tribal people is higher than the national average per capita consumption, 63% deficiency in food grains may be felt by tribal people in general, if TPDS is withdrawn, and the deficit for BPL tribal people may be 82%, TPDS facilitates a reduction of 9.71% in the food expenditure among the total household expenditure of the tribal people in general, share of food to non-food among BPL category of tribals is 55:45 and 40:60 among the APL, Variables, viz. household income, number of members in the family and distance of FPS from tribal settlements etc. have influence on the quantity of rice being purchased by the tribal people from the Fair Price Shops, and there is influence of household income and distance of FPS from tribal settlements on the quantity of rice being purchased by the tribal people from the open market. Rationing with differential pricing on phased allotments, rectification of errors in targeting, anomalies in norms and procedures for classifying tribal people as BPL/APL, exclusive Income Generation for tribal population, paddy cultivation in the landholdings possessed by the tribal people, special drive for allotment of Ration Cards to the tribal people, especially those belonging to the BPL category, Mobile Fair Price Shops in tribal settlements, ensure quality of the food grains distributed through the TPDS, distribution of wheat flour in packed condition instead of wheat through the Fair Price Shops are recommended to address the shortcomings and weaknesses of the TPDS vis-avis the tribal population in Kerala.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Die q-Analysis ist eine spezielle Diskretisierung der Analysis auf einem Gitter, welches eine geometrische Folge darstellt, und findet insbesondere in der Quantenphysik eine breite Anwendung, ist aber auch in der Theorie der q-orthogonalen Polynome und speziellen Funktionen von großer Bedeutung. Die betrachteten mathematischen Objekte aus der q-Welt weisen meist eine recht komplizierte Struktur auf und es liegt daher nahe, sie mit Computeralgebrasystemen zu behandeln. In der vorliegenden Dissertation werden Algorithmen für q-holonome Funktionen und q-hypergeometrische Reihen vorgestellt. Alle Algorithmen sind in dem Maple-Package qFPS, welches integraler Bestandteil der Arbeit ist, implementiert. Nachdem in den ersten beiden Kapiteln Grundlagen geschaffen werden, werden im dritten Kapitel Algorithmen präsentiert, mit denen man zu einer q-holonomen Funktion q-holonome Rekursionsgleichungen durch Kenntnis derer q-Shifts aufstellen kann. Operationen mit q-holonomen Rekursionen werden ebenfalls behandelt. Im vierten Kapitel werden effiziente Methoden zur Bestimmung polynomialer, rationaler und q-hypergeometrischer Lösungen von q-holonomen Rekursionen beschrieben. Das fünfte Kapitel beschäftigt sich mit q-hypergeometrischen Potenzreihen bzgl. spezieller Polynombasen. Wir formulieren einen neuen Algorithmus, der zu einer q-holonomen Rekursionsgleichung einer q-hypergeometrischen Reihe mit nichttrivialem Entwicklungspunkt die entsprechende q-holonome Rekursionsgleichung für die Koeffizienten ermittelt. Ferner können wir einen neuen Algorithmus angeben, der umgekehrt zu einer q-holonomen Rekursionsgleichung für die Koeffizienten eine q-holonome Rekursionsgleichung der Reihe bestimmt und der nützlich ist, um q-holonome Rekursionen für bestimmte verallgemeinerte q-hypergeometrische Funktionen aufzustellen. Mit Formulierung des q-Taylorsatzes haben wir schließlich alle Zutaten zusammen, um das Hauptergebnis dieser Arbeit, das q-Analogon des FPS-Algorithmus zu erhalten. Wolfram Koepfs FPS-Algorithmus aus dem Jahre 1992 bestimmt zu einer gegebenen holonomen Funktion die entsprechende hypergeometrische Reihe. Wir erweitern den Algorithmus dahingehend, dass sogar Linearkombinationen q-hypergeometrischer Potenzreihen bestimmt werden können. ________________________________________________________________________________________________________________

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Este proyecto se ha realizado en la Facultad de Psicología (FPS), de la Universidad de Salamanca (USAL). El lugar de trabajo de los tres profesores del proyecto es el mismo que el lugar de su realización (FPS-USAL). El objetivo del proyecto era elaborar un texto interactivo de prácticas para la asignatura de Psicología del Pensamiento. El sistema de trabajo para lograr nuestro propósito ha sido el de documentación, estudio, elaboración de materiales impresos e informatizados, y creación de un entorno 'web' para la utilización interactiva de dichos materiales. La experiencia se ha aplicado en las clases prácticas de la asignatura antes mencionada. Esta experiencia se ha evaluado con el propósito de saber si se producía algún cambio en el rendimiento de los alumnos respecto a sus capacidades de pensamiento crítico. Los resultados obtenidos suponen una aportación en lo referente a: a) Favorecer el aprendizaje de los alumnos, b) Disminuir el fracaso escolar, c) Potenciar la eficacia de las prácticas y, d) Mejorar las competencias procedimentales esenciales para la titulación de psicología. Los materiales elaborados han sido un texto de prácticas y un conjunto de prácticas interactivas para un entorno 'web' y CD-ROM. El texto de prácticas consta de los siguientes capítulos: 1) Razonamiento práctico, 2) Razonamiento categorial, 3) Razonamiento proposicional, 4) Razonamiento inductivo, 5) Estrategias de representación y de solución de problemas, 6) Toma de decisiones (probabilidad e incertidumbre, sesgos y heurísticos), 7) Aplicación de estrategias creativas, 8) Evaluación de programas de instrucción. El contenido del texto contempla todas las capacidades procedimentales de pensamiento crítico. Las prácticas interactivas recogen las siguientes actividades: 1) Razonamiento práctico, 2) Razonamiento silogístico, 3) Razonamiento condicional, 4) Tarea de selección, 5) Razonamiento inductivo, 6) Heurísticos y decisión, 7) Probabilidad e incertidumbre, 8) Tablas de decisión. Estas actividades prácticas van dirigidas especialmente al desarrollo de las capacidades de pensamiento crítico de naturaleza procedimental. Los materiales utilizados para el desarrollo del proyecto han sido de naturaleza informática. Los materiales elaborados no se han publicado en el momento de su entrega a la Institución financiadora, pero los serán a lo largo del año próximo.