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1.
The change-in-ratio technique is a useful practical procedure for the estimation of game animal population sizes. The major problem with this technique is failure of the assumption that both types of animals are captured or sighted with equal probabilities. Here we extend the change-in-ratio technique to the case where there are two removals with emphasis on the special situation where there are two consecutive single-type removals. The advantage of this extension is that it allows an estimation procedure which is robust to unequal capture or sighting probabilities. It is also possible to test the assumption of equal sighting probabilities. Some numerical results on mean squared error of the population size estimator for the new design and the traditional design are given. The procedure is illustrated on some juvenile grass carp data collected in a small pond where the population size is known. We believe this technique is potentially useful to wildlife and fisheries biologists and that more statistical research would be beneficial.  相似文献   

2.
Xeroradiography, because of its unique phenomenon of "edge enhancement," has some advantages for assessing facial fractures. In 17 of the 19 patients in our pilot study group, this technique was as valuable as, or more so than, plain films. The xerogram done prior to laminagraphy is a useful "map" for the radiologist to use in planning laminagraphic cuts. For the surgeon this technique offers a relatively accurate diagnostic tool, useful early after the facial injury.  相似文献   

3.
We explored the use of multidimensional scaling (MDS) of tree-to-tree pairwise distances to visualize the relationships among sets of phylogenetic trees. We found the technique to be useful for exploring "tree islands" (sets of topologically related trees among larger sets of near-optimal trees), for comparing sets of trees obtained from bootstrapping and Bayesian sampling, for comparing trees obtained from the analysis of several different genes, and for comparing multiple Bayesian analyses. The technique was also useful as a teaching aid for illustrating the progress of a Bayesian analysis and as an exploratory tool for examining large sets of phylogenetic trees. We also identified some limitations to the method, including distortions of the multidimensional tree space into two dimensions through the MDS technique, and the definition of the MDS-defined space based on a limited sample of trees. Nonetheless, the technique is a useful approach for the analysis of large sets of phylogenetic trees.  相似文献   

4.
《Anthrozo?s》2013,26(2):113-117
ABSTRACT

Osgood's Semantic Differential technique was used with a sample of 12 animal names to see if they elicited responses that were distinctively characteristic, and therefore useful in uncovering connotative meaning. The 100 survey participants responded with unanimity to some species, whereas their responses to others were highly variable. Results disclosed a taxonomy of grouping animal names that differed from the normal zoological taxonomy. This suggests that the technique may be useful for discovering the connotations that animals have, and what various animal species may mean to people.  相似文献   

5.
A technique is described which allows perfusion of an isolated, ventilated pig lung with an extracorporeal veno-venous circuit from a support animal. This model is stable for up to 4 h, and avoids some of the disadvantages of alternative small animal and large animal models of lung transplantation. It may be useful in the investigation of factors affecting lung preservation and reperfusion injury.  相似文献   

6.
为进一步探讨单胚RT-PCR技术的适用性,我们测试了3个特定的基因STM、MP和ASKη在拟南芥(Arabidopsisthaliana(L.)Heynh.)早期胚胎发生过程中的动态表达情况.进一步证实以该技术研究某些特定基因的表达动态是可行的.着重探讨了扩增产量与模板量的对应关系、基因组DNA的干扰以及DNase Ⅰ处理过程中的mRNA降解等主要技术问题.结果表明:材料制备时显微操作技术的稳定是确保单胚RT-PCR结果稳定的关键.应尽量缩短DNaseⅠ处理时间,以避免mRNA降解.  相似文献   

7.
Synopsis A method is presented for the histochemical demonstration of native and induced sulphate groups. This method is similar in principle to the Bracco-Curti technique, and is based on the formation, at an acid pH, of insoluble salts formed between sulphate groups and diaminobenzidine. The salt complex is subsequently oxidized by means of osmium tetroxide and, in addition to the brown oxidized diaminobenzidine, osmium black is precipitated.This new method presents some advantages over the Bracco-Curti technique, and it may be useful in the development of a technique for the electron microscopical localization of sulphated mucopolysaccharides.On leave from the Istituto di Anatomia ed Istologia Patologica of the University of Turin and supported by a Fellowship from the Accademia Nazionale dei Lincei.  相似文献   

8.
Eighteen isolates of Giardia duodenalis from animal and human sources were studied for protein differences by polyacrylamide gel electrophoresis and for antigenic differences by immunoblot analysis. The polyacrylamide gels showed that whilst the isolates were for the most part homogeneous in their protein banding patterns, some isolates did show some differences. The immunoblot analysis yielded many bands, including prominent bands of 32 and 66 kilodaltons. Five of the six isolates that showed differences in protein banding pattern also showed differences in antigenic reactivity. Our findings suggest that differences can be seen with the use of immunoblotting and that this technique is a tool that may be useful for isolate differentiation when used in conjunction with other techniques.  相似文献   

9.
Speech production has always been a subject of interest both at the morphological and acoustic levels. This knowledge is useful for a better understanding of all the involved mechanisms and for the construction of articulatory models. Magnetic resonance imaging (MRI) is a powerful technique that allows the study of the whole vocal tract, with good soft tissue contrast and resolution, and permits the calculation of area functions towards a better understanding of this mechanism. Thus, our aim is to demonstrate the value and application of MRI in speech production study and its relationship with engineering, namely with biomedical engineering. After vocal tract contours extraction, data were processed for 3D reconstruction culminating in model construction of some of the sounds of European Portuguese. MRI provides useful morphological data about the position and shape of the different speech articulators, and the biomedical engineering computational tools for its analysis.  相似文献   

10.
A new technique is described for the radioassay of gas-producing reactions. The technique is simple and rapid and is useful for the determination of enzyme activities on a routine basis. The technique involves a closed reaction system and gas-solid scintillation counting with scintillator plastic.  相似文献   

11.
Soil ecosystems are considered biodiversity hotspots. Most of terrestrial organisms depend almost exclusively on soils at least during some part of their life cycle. Although there is an intensive effort to understand the dynamics involving communities of soil animals, most groups are unappreciated in faunal inventories, such as some parasitic Hymenoptera with soil or litter hosts (SLH Hymenoptera), which are considered one of the largest and most diverse groups of soil- or litter-dwelling animals. Contrasting with flight interception traps, techniques that sample soil and litter specimens normally present low costs and easy transportation, being easily replicated within a site. Among them, the Winkler extractor is a useful technique to sample cryptic species associated with leaf litter. The aim of the present work was to describe the SLH Hymenoptera fauna collected in a pool of samples, using a technique to sample leaf litter arthropods. In this work, we report a total of 600 specimens belonging to Hymenoptera (excluding ants), belonging to 15 families distributed within 24 subfamilies, in samples of leaf litter obtained using the Winkler extractor. We observed that this technique is promising for sampling SLH Hymenoptera and should be considered as a complement for inventories of the Hymenoptera fauna.  相似文献   

12.
A numerical dye method for the visualization of unsteady three-dimensional flow calculations is introduced by coupling the unsteady convection-diffusion equation to the Navier-Stokes equation for mass and momentum. This system of equations is descretized using a finite volume projection-like algorithm with generalized coordinates and overset grids. A powerful pressure prediction method is used to accelerate the convergence of the Pressure Poisson equation. To demonstrate the visualization technique, blood flow through the aortic arch region and the three main arterial branches is computed using various Womersley numbers. In this technique, parcels of fluid are followed in time as a function of the cardiac cycle without having to track individual particles, which in turn aids us to better understand some important aspects of the three-dimensionality of the developing unsteady flow. Using this numerical dye method we analyze the strength of the cross flow during the cardiac cycle, the relationship between the penetration of blood into the aortic branches from its relative position in the ascending aortic region and the effects of the Womersley parameter. This technique can be very useful in the design and development of stents where the topology of the device would require understanding where the blood emanating from the heart ends up at the end of the cardiac cycle. Moreover, this method could be useful in investigating the influence of flow and geometry on the local introduction of medication.  相似文献   

13.
Photoacoustic spectroscopy (PAS) is a valuable technique, increasingly applied in clinical and biological analysis. Light absorption properties of urine and body tissue can be obtained more easily by the PAS technique because of its high sensitivity, than by the conventional optical techniques. By observing their absorption properties it is possible to diagnose some diseases and in this study we have used PAS to assess cancerous changes in urine and tissue. Three groups were studied: normal individuals; patients with cancer; and patients with cancer and subsequent inflammation; and the characteristic light absorption peaks obtained for a certain band (240–420 nm). These results were compared with the clinical diagnosis and proved consistent and reliable for the diagnosis of urinary tract cancer subsequently confirmed by operation. This method will probably be a useful tool for the early clinical diagnosis of cancer of the urinary system.  相似文献   

14.
Estimation of binding constants by capillary electrophoresis   总被引:1,自引:0,他引:1  
Capillary electrophoresis (CE) has become a useful technique for measuring binding constants. This review is focused on recent trends in the estimation of binding constants by affinity CE. First, we introduce several mathematical equations in which it is assumed that the stoichiometry of the binding between drug and protein is 1:1 as a simple model. In order to calculate accurate binding constants by affinity CE, several experimental considerations are described in this review. In addition, some recent methodologies, such as partial filling technique and multiple-step ligand injection method, are introduced. Among research publications within 3 years, recent applications for determining binding constants are reviewed.  相似文献   

15.
16.
Nonmicrosurgical use of the radial forearm flap for penile reconstruction   总被引:2,自引:0,他引:2  
Although the era of microsurgical techniques has greatly expanded the number of possible solutions for penile reconstruction, additional options are still needed for some unusual situations when microsurgery is not available or not desired. This article describes the first nonmicrosurgical use of the radial forearm flap for penile reconstruction. With this technique, an osteocutaneous radial forearm flap 15 x 20 cm in size is elevated as a reverse-flow island flap and used to create a neopenis in the classic "tube within a tube" fashion. The neopenis is then transferred to the recipient site as a distant flap, without dividing its vascular connection with the forearm. Once a complete healing is ensured after the following 2 to 3 weeks, the pedicle is cut and the penile reconstruction is completed. Since 1995, this technique was used for total penile reconstruction in four patients: two with congenital penile agenesis, one with penile amputation as a result of a high-voltage electrical injury, and one with total loss of the external genitalia as a result of a shotgun injury. The patients have been followed up for 1 to 4 years. Good results were achieved in all patients. In conclusion, non-microsurgical use of the radial forearm flap seems to be a useful alternative to create an innervated functionally and aesthetically acceptable neopenis when microsurgery is not available or not desired. Although it is a multistage procedure, it is easy to perform. Moreover, this technique provides all well-known advantages of the radial forearm flap in penile reconstruction but does not require the sophisticated equipment and expertise of microsurgery. This is a great advantage that enables surgeons without microsurgical skill to use the radial forearm flap for phallic reconstruction. The author believes that the described technique will be extremely useful in developing countries that have limited resources and where microsurgery is difficult to obtain.  相似文献   

17.
G-protein coupled receptors (GPCRs) are involved in various physiological processes. Therefore, classification of amine type GPCRs is important for proper understanding of their functions. Though some effective methods have been developed, it still remains unknown how many and which features are essential for this task. Empirical studies show that feature selection might address this problem and provide us with some biologically useful knowledge. In this paper, a feature selection technique is introduced to identify those relevant features of proteins which are potentially important for the prediction of amine type GPCRs. The selected features are finally accepted to characterize proteins in a more compact form. High prediction accuracy is observed on two data sets with different sequence similarity by 5-fold cross-validation test. The comparison with a previous method demonstrates the efficiency and effectiveness of the proposed method.  相似文献   

18.
Circadian clocks are thought to regulate retinal physiology in anticipation of the large variation in environmental irradiance associated with the earth’s rotation upon its axis. In this review we discuss some of the rhythmic events that occur in the mammalian retina, and their consequences for retinal physiology. We also review methods of tracing retinal rhythmicity in vivo and highlight the electroretinogram (ERG) as a useful technique in this field. Principally, we discuss how this technique can be used as a quick and noninvasive way of assessing physiological changes that occur in the retina over the course of the day. We highlight some important recent findings facilitated by this approach and discuss its strengths and limitations.  相似文献   

19.
20.
Solitary parathyroid adenomas were correctly located before surgery in 20 out of 21 cases by using 201mT1 and 99mTc in a subtraction technique. The technique was not useful in identifying hyperplastic parathyroid glands. The technique is recommended as a useful procedure before surgery for primary hyperparathyroidism.  相似文献   

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