FORMATION OF MALE FERTILITY IN ONTOGENESIS

The main human species mission is fertility, which is an important point of the concept of health in general and of reproductive health in particular. Endocrinologists, obstetrician-gynaecologists, urologists and paediatricians are focused in this field of medicine. A decline in male fertility of up to 30–35% results in infertility which becomes serious concerns growing for human population. Many of the problems that lead to impaired male fertility are rooted in childhood, or rather, in prenatal ontogenesis. The penetration of vascular-bed substances into the cavity of the seminiferous tubules depends on the maturity and functional status of the structures constituting the blood-testicular barrier (BTB). A breach of BTB results in damage to the sperm epithelium and, as a consequence, in different grades of impairment of spermatogenesis. Among the diseases that predispose men to infertility varicocele predominates (up to 30%). One of the reasons for infertility is the impaired integrity of BTB when the process of spermatogenesis changes, sometimes in combination with infection, trauma, and toxic effects. Given the unfavorable prognosis of the consequences of these diseases in children, their careful and timely diagnosis is important. Fertility estimation places special emphasis on the state of BTB, which can be determined by the content of claudine-11, antisperm antibodies, inhibin B, and other markers.

Using Census Returns and the Own-Children Method to Measure Marital Fertility in Rawtenstall, 1851-1901

The incompleteness of Victorian census returns of marriage and birth records for England and Wales, and the high costs of using civil and church records, have greatly restricted research into the timing and character of the decline in marital fertility in the second half of the 19th century. This article argues that, in spite of these limitations, the census returns provide enough data to allow the well-known the 'Own-children method of fertility estimation', when used within Bongaarts' framework for analysing the proximate determinants of fertility, to derive estimates of total and age-specific marital fertility for women 15 to 49 years of age. It uses data from the census returns for the town of Rawtenstall, a small cotton textile manufacturing town in north-east Lancashire, to generate these estimates and to test their credibility against other well respected measures of marital fertility for England and Wales.

Pollen morphology of four endemic species of Pedicularis L. from alpine zone of the Deosai Plateau, Himalayan range

The pollen morphology with special reference to exine sculpturing of four species of the genus Pedicularis L. has been examined by light and scanning electron microscope. Comparative pollen analysis was made based on the type of pollen, shape in polar and equatorial views, P/E ratio, exine thickness and sculpturing of pollen. In this study, two types of pollen aperture configuration known in the genus were observed i.e., trisyncolpate and bi-syncolpate. Pollen grains with microscabrate ornamentation were found in bi-syncolpate pollen for the first time. Pollen fertility estimation ranged from 87-95%, which shows that pollen flora of selected species is well established in Alpine zone.DOI: http://dx.doi.org/10.3329/bjpt.v19i1.10935Bangladesh J. Plant Taxon. 19(1): 1-5, 2012 (June)

Molecular characterization of two natural hybrids from the Iberian Peninsula: Ranunculus × luizetii and R. × peredae (Ranunculaceae)

Two nothospecies, Ranunculus × luizetii and R. × peredae (Ranunculaceae), were analyzed and discussed. For this purpose, Amplified Fragment Length Polymorphism (AFLP) markers, nuclear rDNA sequences (ITS1, 5.8S and ITS2) and pollen viability were conducted. The profiles of these hybrid samples were compared to their putative progenitors. Several additive polymorphic sites detected in the ITS sequences of the hybrid samples (R. × luizetii and R. × peredae) also confirmed their derived origins from ribotypes of their parental taxa (R. parnassiifolius subsp. parnassiifolius × R. pyrenaeus; R. amplexicaulis × R. cabrerensis subsp. cabrerensis, respectively). Despite the lack of exclusive AFLP markers reported in both hybrids, presumably due to effects of introgression, the concerted evolution of many rDNA polymorphisms towards either of the parental ribotypes indicated their ancient origin. Pollen fertility estimation in R. × luizetii presented a mean value of 60.58%, which showed that hybrid samples are well established and fertile. However, a larger difference was observed in R. × peredae, where the mean value of pollen fertility was very low (18.91%).

Monitoring of German Fertility: Estimation of Monthly and Yearly Total Fertility Rates on the Basis of Preliminary Monthly Data

This paper introduces a set of methods for estimating fertility indicators in the absence of recent and short-term birth statistics. For Germany, we propose a set of straightforward methods that allow for the computation of monthly and yearly total fertility rates (mTFR) on the basis of preliminary monthly data, including a confidence interval. The method for estimating most current fertility rates can be applied when no information on the age structure and the number of women exposed to childbearing is available. The methods introduced in this study are useful for calculating monthly birth indicators, with minimal requirements for data quality and statistical effort. In addition, we suggest an approach for projecting the yearly TFR based on preliminary monthly information up to June.