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Chonopeltis australis (Crustacea) male reproductive system morphology; Sperm transfer and review of reproduction in Branchiura 下载免费PDF全文
Lourelle Alicia Martins Neethling Annemariè Avenant‐Oldewage 《Journal of morphology》2015,276(2):209-218
The morphology of the male reproductive system as well as sperm transfer in Branchiura has been described for Dolops ranarum and Argulus japonicus. In this study, the reproductive system and accessory structures are described for male Chonopeltis australis using histology, light microscopy, and scanning electron microscopy. For the first time, we describe sperm transfer by means of a spermatophore in this genus. The internal and external morphology and mechanism of sperm transfer is compared with other Branchiura, where it has been described. The morphology of the reproductive system of C. australis is similar to that of D. ranarum while the accessory structures and the spermatophore produced are similar to that of A. japonicus. A revision of the definition of Branchiura with respect to reproduction is provided. J. Morphol. 276:209–218, 2015. © 2014 Wiley Periodicals, Inc. 相似文献
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Morphological diversity and evolution of the spermatozoon in the mouse‐related clade of rodents 下载免费PDF全文
William G. Breed Chris M. Leigh Ken P. Aplin Adel A.B. Shahin Nico L. Avenant 《Journal of morphology》2014,275(5):540-547
Most species in the three highly speciose families of the mouse‐related clade of rodents, the Muridae, Cricetidae, and Nesomyidae (superfamily Muroidea), have a highly complex sperm head in which there is an apical hook but there are few data available for the other related families of these rodents. In the current study, using light and electron microscopies, we investigated the structure of the spermatozoon in representative species of four other families within the mouse‐related clade, the Dipodidae, Spalacidae, Pedetidae, and Heteromyidae, that diverged at or near the base of the muroid lineage. Our results indicate that a diverse array of sperm head shapes and tail lengths occurs but none of the species in the families Spalacidae, Dipodidae, or Pedetidae has a sperm head with an apical hook. By contrast, a rostrally extending apical hook is present in spermatozoa of members of the Family Heteromyidae which also invariably have comparatively long sperm tails. These findings suggest that the hook‐shaped sperm head in the murid, cricetid, and nesomyid rodents evolved after divergence of this lineage from its common ancestor with the other families of the mouse‐related clade, and that separate, and independent, convergent evolution of a similar sperm head form, and long sperm tail, occurred in the Heteromyidae. J. Morphol. 275:540–547, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
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Gerhard H. Janse van Rensburg Ute Dagmar Feucht Jennifer Makin Nanya le Clus Theunis Avenant 《PLoS medicine》2021,18(3)
BackgroundHuman migration is a worldwide phenomenon that receives considerable attention from the media and healthcare authorities alike. A significant proportion of children seen at public sector health facilities in South Africa (SA) are immigrants, and gaps have previously been noted in their healthcare provision.The objective of the study was to describe the characteristics and differences between the immigrant and SA children admitted to Kalafong Provincial Tertiary Hospital (KPTH), a large public sector hospital in the urban Gauteng Province of SA.Methods and findingsA cross-sectional study was conducted over a 4-month period during 2016 to 2017. Information was obtained through a structured questionnaire and health record review. The enrolled study participants included 508 children divided into 2 groups, namely 271 general paediatric patients and 237 neonates. Twenty-five percent of children in the neonatal group and 22.5% in the general paediatric group were immigrants. The parents/caregivers of the immigrant group had a lower educational level (p < 0.0001 neonatal and paediatric), lower income (neonatal p < 0.001; paediatric p = 0.024), difficulty communicating in English (p < 0.001 neonatal and paediatric), and were more likely residing in informal settlements (neonatal p = 0.001; paediatric p = 0.007) compared to the SA group. In the neonatal group, there was no difference in the number of antenatal care (ANC) visits, type of delivery, gestational age, and birth weight. In the general paediatric group, there was no difference in immunisation and vitamin A supplementation coverage, but when comparing growth, the immigrant group had more malnutrition compared to the SA group (p = 0.029 for wasting). There was no difference in the prevalence of maternal human immunodeficiency virus (HIV) infection, with equally good prevention of mother-to-child transmission (PMTCT) coverage. There was also no difference in reported difficulties by immigrants in terms of access to healthcare (neonatal p = 0.379; paediatric p = 0.246), although a large proportion (10%) of the neonates of immigrant mothers were born outside a medical facility.ConclusionsAlthough there were health-related differences between immigrant and SA children accessing in-hospital care, these were fewer than expected. Differences were found in parental educational level and socioeconomic factors, but these did not significantly affect ANC attendance, delivery outcomes, immunisation coverage, HIV prevalence, or PMTCT coverage. The immigrant population should be viewed as a high-risk group, with potential problems including suboptimal child growth. Health workers should advocate for all children in the community they are serving and promote tolerance, respect, and equal healthcare access. 相似文献
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During 1982–83 fish parasitological surveys were carried out in 15 dam reservoirs in the Transvaal. The fish ectoparasite Dolops ranarum was found on eight different fish species of which Oreochromis mossambicus. Clarias gariepinus and Barbus marequensis are regarded as main hosts. Distribution records and infestation statistics are presented. It was found that D. ranarum is restricted to the Limpopo Drainage System. An evaluation of site preference on host fish reveals that the mouth cavity, in the case of O. mossambicus , and skin and fins, in the case of C. gariepinus , were the sites most intensively infested by this parasite. 相似文献