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Incomplete gene structure prediction with almost 100% specificityChin, See Loong 30 September 2004 (has links)
The goals of gene prediction using computational approaches are to determine gene location and the corresponding functionality of the coding region. A subset of gene prediction is the gene structure prediction problem, which is to define the exon-intron boundaries of a gene. Gene prediction follows two general approaches: statistical patterns identification and sequence similarity comparison. Similarity based approaches have gained increasing popularity with the recent vast increase in genomic data in GenBank. The proposed gene prediction algorithm is a similarity based algorithm which capitalizes on the fact that similar sequences bear similar functions. The proposed algorithm, like most other similarity based algorithms, is based on dynamic programming. Given a genomic DNA, X = x1 xn and a closely related cDNA, Y = y1 yn, these sequences are aligned with matching pairs stored in a data set. These indexes of matching sets contain a large jumble of all matching pairs, with a lot of cross over indexes. Dynamic programming alignment is again used to retrieve the longest common non-crossing subsequence from the collection of matching fragments in the data set. This algorithm was implemented in Java on the Unix platform. Statistical comparisons were made against other software programs in the field. Statistical evaluation at both the DNA and exonic level were made against Est2genome, Sim4, Spidey, and Fgenesh-C. The proposed gene structure prediction algorithm, by far, has the best performance in the specificity category. The resulting specificity was greater than 98%. The proposed algorithm also has on par results in terms of sensitivity and correlation coeffcient. The goal of developing an algorithm to predict exonic regions with a very high level of correctness was achieved.
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Aerobininkių aerobinis pajėgumas testuojant specifinėmis ir nespecifinėmis sąlygomis / Aerobic capacity of aerobic gymnasts while testing in specific and non-specific conditionsVaitkevičius, Deimantas 16 May 2006 (has links)
Aerobic capacity of aerobic gymnasts while testing in specific and non-specific conditions
The aim of the study: to determine an aerobic capacity of aerobic gymnasts while testing in specific and non-specific conditions.
Objectives:
· To compare submaximum heart rate and respiratory indices during treadmill and step tests.
· To compare maximum heart rate and respiratory indices during treadmill and step tests.
· To evaluate step test’s using opportunities for testing an aerobic capacity of aerobic gymnasts.
Methods:
1. Continuously increasing step test.
2. Continuously increasing treadmill test
3. Measurement of respiratory gas exchange.
4. HR monitoring and recording.
5. Measurement of blood lactate concentration.
6. Anthropometrical measurements.
The hypothesis of the study. Incremental increasing step test is able for evaluation of an aerobic capacity, heart rate and respiratory indices, especially submaximum, while testing under specific conditions, i. e. performing physical exercises on the aerobic platform dosing physical load according to the tempo of music.
Practical application. The results access the physiological knowledges about aerobic gymnasts aerobic capacity. These data can be used for individualization of the physical loads in aerobic gymnastics.
Originality of the study. First time using respiratory gas exchange telemetric system was performed an incremental increasing step test, while the physical load was dosed by music rhythm. The aerobic capacity of... [to full text]
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Empirical Likelihood Based Confidence Intervals for the Difference between Two Sensitivities of Continuous-scale Diagnostic Tests at a Fixed Level of SpecificityYao, Suqin 28 November 2007 (has links)
Diagnostic testing is essential to distinguish non-diseased individuals from diseased individuals. The sensitivity and specificity are two important indices for the diagnostic accuracy of continuous-scale diagnostic tests. If we want to compare the effectiveness of two tests, it is of interest to construct a confidence interval for the difference of the two sensitivities at a fixed level of specificity. In this thesis, we propose two empirical likelihood based confidence intervals (HBELI and HBELII) for the difference of two sensitivities at a predetermined specificity level. Simulation studies show that when correlation between the two test results exists, HBELI and HBELII intervals perform better than the existing bootstrap based BCa, BTI and BTII intervals due to shorter interval lengths. However, when there is no correlation, BCa, BTI and BTII intervals outperform HBELI and HBELII intervals due to better coverage probability in most simulation settings.
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Some Contributions in Statistical Discrimination of Different Pathogens Using Observations through FTIRWang, Dongmei 01 December 2009 (has links)
Fourier Transform Infrared (FTIR) has been use to discriminate different pathogens by signals from cells infected with these versus normal cells as references. To do the statistical analysis, Partial Least Square Regression (PLSR) was utilized to distinguish any two kinds of virus‐infected cells and normal cells. Validation using Bootstrap method and Cross‐validations were employed to calculate the shrinkages of Area Under the ROC Curve (AUC) and specificities corresponding to 80%, 90%, and 95% sensitivities. The result shows that our procedure can significantly discriminate these pathogens when we compare infected cells with the normal cells. On the height of this success, PLSR was applied again to simultaneously compare two kinds of virus‐infected cells and the normal cells. The shrinkage of Volume Under the Surface (VUS) was calculated to do the evaluation of model diagnostic performance. The high value of VUS demonstrates that our method can effectively differentiate virus‐infected cells and normal cells.
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STRUCTURAL AND FUNCTIONAL STUDIES OF SYNAPTIC ENZYMESLim, Eun Jeong 01 January 2006 (has links)
Thimet oligopeptidase (TOP, EC 3.4.24.15) and neurolysin (EC 3.4.24.16) are zincdependent metallopeptidases that metabolize small bioactive peptides. The two enzymes share60 % sequence identity and their crystal structures demonstrate that they adopt nearly identicalfolds. They generally cleave at the same sites, but they recognize different positions on somepeptides, including neurotensin, a 13-residue peptide involved in modulation of dopaminergiccircuits, pain perception, and thermoregulation.On the basis of crystal structures and previous mapping studies, four residues(E469/R470, M490/R491, H495/N496, and R498/T499, TOP residues listed first) in thesubstrate-binding channel appear positioned to account for differences in specificity. TOPmutated to the neurolysin residues at all four position cleaves neurotensin at the neurolysin siteand neurolysin mutated to the TOP residues at all four sites cleaves at the TOP position. Using aseries of constructs mutated at only three sites, it was determined that only two of the mutations,E469/R470 and R498/T499, are required to swap the specificity of TOP and neurolysin. Theseresults were confirmed by testing the two mutation constructs, and either single mutant of TOPshown an intermediate specificity, cleaving at both sites.Crystal structures of the two mutation constructs of TOP and neurolysin unligandedforms, the mutations do not perturb local structure, but side chain conformations at theR498/T499 position differ from those of the mimicked enzyme. A model for differentialrecognition of neurotensin based on differences in surface charge distribution in the substratebinding sites is proposed. The model is supported by finding that reducing the positive charge onthe peptide results in cleavage at both hydrolysis sites.This dissertation also includes a description of the production and crystallization trials ofhuman neprilysin (E.C. 3.4.24.11), which will be used as another model system for studyingspecificity in metallopeptidases. In addition, the production and crystallization, and crystalcharacterization of human choline acetyltransferase (EC 2.3.1.6) is described.
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THREE-DIMENSIONAL QUANTITATIVE ANALYSIS OF THE TRAJECTORY OF THE FOOT WHILE RUNNINGCunningham, Thomas J. 01 January 2007 (has links)
Exercising the leg in a manner similar to running is theorized to have the potential effect of increasing performance and reducing occurrence of injuries in running athletes. Development of an exercise device that can help facilitate this method of specificity training could be beneficial to the sports community and should be investigated. Understanding the trajectory of the foot during the running gait is primary to further pursue this concept. 26 running athletes of varying characteristics participated in this study. Each subjects sex, age, weight, height, leg length, activity level and participation amount in their respective sport was recorded. Retro-reflective cameras captured the three-dimensional trajectory of each subjects right leg while running at speeds of 2, 3.8, 4.52 and 5.36 m/s for 10-15 seconds on a treadmill, respectively. The range of foot movement in each cardinal plane was determined for each speed. An ANCOVA revealed that leg length was the most determinate factor in trajectory range differences among subjects. Subjects were subsequently divided into quartiles based on leg length where further analysis revealed that foot displacement increased vertically and horizontally in the sagittal plane with increases in speed while trajectory in the third plane remained constant and substantially less in magnitude.
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Structural studies of two anti-carbohydrate antibodiesEvans, Dylan W. 13 May 2013 (has links)
This thesis is focused on determining the structures of two anti-carbohydrate antibodies to understand how they achieve their specificity toward antigen.
First, the structure of the antigen-binding fragment from the monoclonal antibody S64-4 in complex with a pentasaccharide bisphosphate fragment from chlamydial lipopolysaccharide (LPS) has been determined by x-ray diffraction to 2.6 Å resolution. Like the well-characterized antibody S25-2, S64-4 displays a pocket formed by the residues of germline sequence corresponding to the heavy and light chain V gene segments that binds the terminal Kdo (3-deoxy-α-D-manno-oct-2-ulopyranosonic acid) residue of the antigen; however, although S64-4 shares the same heavy chain V gene segment as S25-2, it has a different light chain V gene segment. The new light chain V gene segment codes for a combining site that displays greater avidity, different specificity, and allows a novel antigen conformation that brings a greater number of antigen residues into the combining site than possible in S25-2. Further, while antibodies in the S25-2 family use complementarity determining region (CDR) H3 to discriminate among antigens, S64-4 achieves its specificity via the new light chain V gene
segment and resulting change in antigen conformation. These structures reveal an intriguing parallel strategy where two different combinations of germline-coded V gene segments can act as starting points for the generation of germline antibodies against chlamydial antigens and show how anti-carbohydrate antibodies can exploit the conformational flexibility of this class of antigens to achieve high avidity and specificity independently of CDR H3.
Second, the structure of a rabbit, single chain variable fragment against terminal mannose-6-phosphate (Man6P) residues, termed scFv M6P-1, has been determined by x-ray diffraction to 2.7 Å resolution with Man6P in the binding site. The Man6P pathway is the predominant pathway that transports acid hydrolases from the trans-Golgi to endosomes. Newly synthesized hydrolases first require the generation of Man6P markers before they can be transported. Maintaining a full complement of hydrolases within lysosomes is essential as failure to do so results in a number of different lysosomal storage diseases. Due to its specificity, scFv M6P-1 is able to diagnose lysosomal storage diseases mucolipidosis II and mucolipidosis III. scFv M6P-1 is also able to purify Man6P containing proteins which may be useful for enzyme replacement therapies. Additionally, scFv M6P-1 is one of the first structures of an antibody fragment that exhibits high specificity for a single carbohydrate residue and is one of the first structures of a rabbit antibody fragment. The specificity of scFv M6P-1, which gives it these unique attributes, is revealed in the structure where multiple hydrogen bonds are seen between the antibody’s heavy chain and the mannose ring while two salt bridges are observed between the antibody’s light chain and the phosphate moiety. Finally, scFv M6P-1 binds in such a way as to allow binding to proteins possessing terminal Man6P residues. Crystallographic challenges that arose during this research included poor crystal growth as well as twinning and these are explored while the structure of scFv M6P-1 complex with Man6P is analysed. / Graduate / 0487 / 0982 / 0307 / dyl.w.evans@gmail.com
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Investigation of SH3 Domain Specificity through the Study of Cross-reactive Domains from Yeast Proteins Nbp2p and Bem1p / Investigation of SH3 Domain Specificity through the Study of Cross-reactive Domains from Yeast Proteins Nbp2p and Bem1pGorelik, Maryna 09 January 2012 (has links)
Protein interactions are often mediated through binding of protein interaction domains to short peptide motifs. However, how the specificity of interactions is regulated within domain families is not well understood. In this thesis, I investigated this issue through the study of two cross-reactive SH3 domains from the yeast adaptor proteins Nbp2p and Bem1p. Despite low sequence similarity and different cellular roles, the Nbp2p SH3 and Bem1p SH3b domains recognize targets containing the same consensus sequences, raising the question of how the specificity of these domains is controlled. The Bem1p SH3b domain is also unusual in containing a 40 amino acid long C-terminal extension required for folding and interaction with the Cdc42p GTPase, which I also investigated in this thesis.
I demonstrated that although Nbp2p SH3 and Bem1p SH3b domains recognize the same consensus sequence, each domain possesses its own unique specificity within the context of eight yeast peptides. Through structural and mutagenesis studies, I demonstrated that the Nbp2p SH3 and Bem1p SH3b domains employ different mechanism for binding, explaining how each domain can still possess its own unique specificity, while recognizing the same consensus sequence. I found that the specificity of Bem1 SH3b domain is largely regulated through inhibitory interactions, where a conserved residue in the binding interface serves to decrease binding to non-specific targets. Most significantly I observed that reducing the specificity of Bem1 SH3b domain, without reducing its binding affinity decreases its ability to function in vivo.
My structural and mutagenesis studies with the Bem1p SH3b domain also demonstrated that its C-terminal extension is involved in peptide binding surface and creates a separate surface required for interaction with Cdc42p. I also showed that the Bem1p SH3b domain is capable of simultaneously interacting with peptide targets and Cdc42p, suggesting a role for this domain in Cdc42p mediated activation.
Overall, my findings demonstrated the ability of SH3 domains to perform complex functions and bind their targets with finely tuned specificity. Most importantly, I demonstrated the significance of negative interactions for specificity determination and the importance of precise specificity for in vivo function.
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Analyses of Host Specificity, Immune Interactions and New Virulence Candidates of Pseudomonas syringaeSanina, Natali 26 February 2009 (has links)
We studied the host specificity, interactions with plant immune systems, and virulence factors of the phytopathogenic Type III secretion system-carrying bacterium Pseudomonas syringae. In studying host specificity, we ran growth and pod assays using seventeen pathovars of P. syringae on kidney bean hosts. We tracked bacterial growth numbers over six days and compared pathovar growth patterns. To study immune interactions with host plants, we performed effector-triggered immunity induction and suppression assays with individual effectors in Arabidopsis thaliana to determine whether effector evolutionary age was related to
resultant plant immune responses. No correlations were observed. To generate candidate virulence effectors, we sequenced mRNA from seven P. syringae pathovars grown in inducing media and pulled out hits to virulence-related genes.
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Investigation of SH3 Domain Specificity through the Study of Cross-reactive Domains from Yeast Proteins Nbp2p and Bem1p / Investigation of SH3 Domain Specificity through the Study of Cross-reactive Domains from Yeast Proteins Nbp2p and Bem1pGorelik, Maryna 09 January 2012 (has links)
Protein interactions are often mediated through binding of protein interaction domains to short peptide motifs. However, how the specificity of interactions is regulated within domain families is not well understood. In this thesis, I investigated this issue through the study of two cross-reactive SH3 domains from the yeast adaptor proteins Nbp2p and Bem1p. Despite low sequence similarity and different cellular roles, the Nbp2p SH3 and Bem1p SH3b domains recognize targets containing the same consensus sequences, raising the question of how the specificity of these domains is controlled. The Bem1p SH3b domain is also unusual in containing a 40 amino acid long C-terminal extension required for folding and interaction with the Cdc42p GTPase, which I also investigated in this thesis.
I demonstrated that although Nbp2p SH3 and Bem1p SH3b domains recognize the same consensus sequence, each domain possesses its own unique specificity within the context of eight yeast peptides. Through structural and mutagenesis studies, I demonstrated that the Nbp2p SH3 and Bem1p SH3b domains employ different mechanism for binding, explaining how each domain can still possess its own unique specificity, while recognizing the same consensus sequence. I found that the specificity of Bem1 SH3b domain is largely regulated through inhibitory interactions, where a conserved residue in the binding interface serves to decrease binding to non-specific targets. Most significantly I observed that reducing the specificity of Bem1 SH3b domain, without reducing its binding affinity decreases its ability to function in vivo.
My structural and mutagenesis studies with the Bem1p SH3b domain also demonstrated that its C-terminal extension is involved in peptide binding surface and creates a separate surface required for interaction with Cdc42p. I also showed that the Bem1p SH3b domain is capable of simultaneously interacting with peptide targets and Cdc42p, suggesting a role for this domain in Cdc42p mediated activation.
Overall, my findings demonstrated the ability of SH3 domains to perform complex functions and bind their targets with finely tuned specificity. Most importantly, I demonstrated the significance of negative interactions for specificity determination and the importance of precise specificity for in vivo function.
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