Semen analysis and sperm function testing

Despite controversy regarding the clinical value of semen analysis, male fertility investigation still relies on a standardized analysis of the semen parameters. This is especially true for infertility clinics in both developing and developed countries. Other optional tests or sophisticated technologies have not been widely applied. The current review addresses important changes in the analysis of semen as described in the new World Health Organization （WHO） manual for semen analysis. The most important change in the manual is the use of evidence-based publications as references to determine cutoff values for normality. Apart from the above mentioned changes, the initial evaluation and handling methods remain, in most instances, the same as in previous editions. Furthermore, the review evaluates the importance of quality control in andrology with emphasis on the evaluation of sperm morphology. WHO sperm morphology training programmes for Sub-Saharan countries were initiated at Tygerberg Hospital in 1995. The external qualitY control programme has ensured that the majority of participants have maintained their morphological reading skills acquired during initial training. This review reports on current sperm functional tests, such as the induced acrosome reaction, and sperm-zona pellucida binding assays, as well as the impact of sperm quality in terms of DNA integrity, and the relationship of sperm function tests to sperm morphology.

Concentrative function and its primary application

In this paper, a concentrative function used in statistics is designed to present the extent in which an elementary field concentrates in the spatial distribution. Its characteristics are discussed and its availability proved. From its application in the atmospheric and oceanic sciences, we can find some interesting phenomena. For example, there is a clear seasonal concentricity in the occurrence of storms in every oceanic area in a year. The storm-dense-months correspond to such an geographical place that goes around anti-clockwise in the tropical oceanic areas. The spatial concentricity of SST and that of cloud change with time in a year in a similar way, that is, the higher occurrence of storms, the higher concentricity of M and cloud, maybe the higher possibility of floods, which shows possibly that SST and its distribution play an important role in the formation of cloud and that the formation of storms contributes to the concentration of the cloud.

A comparative study on three EOF analysis techniques using decades of Arctic sea-ice concentration data

Change in Arctic sea ice extent is one of the indicators of global climate changes. Spatio-temporal change and change patterns can be identified using various methods to facilitate human understanding global climate changes. Three empirical orthogonal function(EOF) techniques are discussed and applied to decades of sea-ice concentration(SIC) dataset in Arctic area for identifying independent patterns. It was found that: 1) discrepancies exist in magnitude and scope for each EOF pattern, however, the first two leading EOFs of variability possess high similarities in structure and shape; 2) Even though there are somewhat differences in amplitude of each PC mode, the first two leading PC modes maintain consistent in overall trend and periodicity; 3) There are significant discrepancies and inconsistencies in the third and fourth leading EOF and PC modes. The accuracies of three techniques are further validated in representing the physical phenomena of SIC anomaly patterns.