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81.
Aeberhardt K Laumer JY Bouquerand PE Normand V 《International journal of biological macromolecules》2005,36(5):275-282
The determination of apparent persistence length and radius of gyration of maltodextrins in water is achievable through high-resolution ultrasonic spectroscopy measurements. Classical hydration number for those carbohydrates is characteristic of an apparent persistence degree of polymerisation of the polymer. A force-field based molecular modeling of a 10DP malto-oligomer allows measurement of the corresponding length for the lowest energetic conformation in solution. A good agreement between the apparent radii of gyration determined by this technique and the freely rotating polymer chain model is found with radii of gyration calculated from the intrinsic viscosity. 相似文献
82.
Non-linear cancer classification using a modified radial basis function classification algorithm 总被引:1,自引:0,他引:1
Summary This paper proposes a modified radial basis function classification algorithm for non-linear cancer classification. In the
algorithm, a modified simulated annealing method is developed and combined with the linear least square and gradient paradigms
to optimize the structure of the radial basis function (RBF) classifier. The proposed algorithm can be adopted to perform
non-linear cancer classification based on gene expression profiles and applied to two microarray data sets involving various
human tumor classes: (1) Normal versus colon tumor; (2) acute myeloid leukemia (AML) versus acute lymphoblastic leukemia (ALL).
Finally, accuracy and stability for the proposed algorithm are further demonstrated by comparing with the other cancer classification
algorithms. 相似文献
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Poland D 《Biopolymers》2004,73(2):216-228
In this article we give a new method for the calculation of DNA melting profiles. Based on the matrix formulation of the DNA partition function, the method relies for its efficiency on the fact that the required matrices are very sparse, essentially reducing matrix multiplication to vector multiplication and thus making the computer time required to treat a DNA molecule containing N base pairs proportional to N(2). A key ingredient in the method is the result that multiplication by the inverse matrix can also be reduced to vector multiplication. The task of calculating the melting profile for the entire genome is further reduced by treating regions of the molecule between helix-plateaus, thus breaking the molecule up into independent parts that can each be treated individually. The method is easily modified to incorporate changes in the assignment of statistical weights to the different structural features of DNA. We illustrate the method using the genome of Haemophilus influenzae. 相似文献
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Thangavel Rajagopal Govindaraju Archunan Pitchairaj Geraldine 《Behavioural processes》2010,85(1):58-67
In ungulates the process of chemical communication by urinary scent marking has been directly related to reproductive dominance, territorial defense and proximity to resources. The differences in the frequency of urine marking and chemical composition of urine of males Antelope cervicapra before, during and after the dominance hierarchy period were assessed. The variations in the urine marking and its chemical profiles of dominant males (n = 9), bachelors (n = 5) and sub-adult males (n = 5) were compared to find out how the dominance hierarchy influences the confined blackbuck herd under semi-natural captive conditions. The frequency of urine marking is significantly higher (p < 0.001) in dominant males. Twenty-eight major constituents were identified in the urine of dominant males (before, during and after the dominance hierarchy period), bachelor and sub-adult males. Among these, three specific compounds namely, 3-hexanone (I), 6-methyl-5-hepten-2-one (II) and 4-methyl-3-heptanone (III) were seen only in dominant males urine during the dominance hierarchy period. Based on the behavioural observation and the unique chemical constituents in the urine, it is concluded that the dominant male scent odor suppresses aggression, scent marking, scent production and territorial patrolling activities of subordinate males, through which the dominant male establish their hierarchy and attains success in reproduction. 相似文献
88.
The coefficient of variation CV (%) is widely used to measure the relative variation of a random variable to its mean or to assess and compare the performance of analytical techniques/equipments. A review is made of the existing multivariate extensions of the univariate CV where, instead of a random variable, a random vector is considered, and a novel definition is proposed. The multivariate CV obtained only requires the calculation of the mean vector, the covariance matrix and simple quadratic forms. No matrix inversion is needed which makes the new approach equally attractive in high dimensional as in very small sample size problems. As an illustration, the method is applied to electrophoresis data from external quality assessment in laboratory medicine, to phenotypic characteristics of pocket gophers and to a microarray data set. 相似文献
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