ABSTRACT Monthly collections of the African yellow bat, Scotophilus dinganii, were made in the Kr... more ABSTRACT Monthly collections of the African yellow bat, Scotophilus dinganii, were made in the Kruger National Park. Examination of serially sectioned reproductive tracts of females showed that the African yellow bat is a monoestrous species and that insemination, ovulation and fertilization took place during mid to late autumn (April to May). Early embryonic development of normally two embryos (one in each uterine horn) was retarded and implantation delayed until mid-winter (July), when the blastocysts implanted.
ASMOSIA 5: Interdisciplinary Studies on Ancient Stone, 2002
No single analytical technique is usually sufficient to attribute a marble object unambiguously t... more No single analytical technique is usually sufficient to attribute a marble object unambiguously to a particular quarry source in the Mediterranean world, and a number of research groups have emphasized the importance of using a multi-method approach. One exception to this rule is Cape Vathy on the island of Thasos in the northern Aegean, an important marble source in antiquity. Cape Vathy appears to have been the only significant source of dolomitic marble used in the Mediterranean region. Stable isotope analyses of classical sculptures made of dolomitic marble are all consistent with a Thasian origin, indicating that a simple, inexpensive, and essentially non-destructive "dolomite test" can be used to determine whether a marble piece is from Cape Vathy. Several hundred samples were collected from Greek and Roman statues and reliefs in museums and private collections in Europe and the United States that appeared to have been carved in marble from Cape Vathy on Thasos. X-ray diffraction (XRD) was used to test for the presence of dolomite, with the finding that 75% of the "Thasian" appearing sculptures were in fact dolomitic. Stable isotope analyses of the dolomitic sculptures have reconfirmed their Thasian attribution; these analytical data serve to further refine the isotopic field for Thasian marble and may potentially allow the identification of discrete quarry areas exploited at different times in the past. Isotopic analyses of the calcite marble sculptures add to the more than 100 analyses that we have reported at ASMOSIA III and IV. As the number of sculptures with quarry attributions grows, contributions are made to our understanding of chronological, geographic, and art historical patterns in marble use.
The malfunctioning or even absence of provincial heritage agencies in various parts of the countr... more The malfunctioning or even absence of provincial heritage agencies in various parts of the country, which are now required by the National Heritage Act, is playing havoc with plans to investigate new archaeological and palaeontological sites.
Little is known about peptide-storing endocrine cells in the gut of the Nile crocodile. As in the... more Little is known about peptide-storing endocrine cells in the gut of the Nile crocodile. As in the case of other reptiles, particularly the alligator, a limited range of peptide-storing cells was found in the gut of the crocodile. They were somatostatin, glucagon, gastrin, neurotensin and pancreatic polypeptide. The topographical distribution of cells immunoreactive to somatostatin and gastrin in the gut of the crocodile is comparable to the situation in the alligator. Glucagon and neurotensin immunoreactive cells have a much wider distribution in the gastro-intestinal tract of the crocodile compared to the alligator. Cholecystokinin and bombesin cells previously reported in the small intestine of the alligator were not detected in this study. This is the first report to demonstrate pancreatic polypeptide and serotonin immunoreactivity in the gut of a crocodilian specie.
Although the histology of the intestinal tract of Crocodylus niloticus is touched on in overall s... more Although the histology of the intestinal tract of Crocodylus niloticus is touched on in overall studies on reptilian intestinal tract, a more comprehensive light microscopical study on this area is lacking. Specimens for histological examination were taken from the duodenum, the jejunum, the ileum and the rectum. The data obtained revealed that the mucosa is thrown into folds and simple, slightly branched tubular intestinal glands. The mucosal folds diminished in height and eventually disappeared upon reaching the ileorectal junction. The epithelium covering the folds and crypts was of the simple columnar type. Clear marginal cells, goblet cells and argentaffin cells were observed throughout the intestinal tract. No Paneth cells were seen in this study. The lamina propria was rich in lymphocytic infiltrations while the muscularis mucosa consisted mainly of an outer longitudinal layer, the inner circular layer being rudimentary or absent. The submucosa was extremely narrow, and the circular and longitudinal layers of the tunica muscularis contained distinct layers of dense fibrous connective tissue. The histology of the intestinal tract of C. niloticus is shown to be in line with the situation in crocodilians and also exhibits a resemblance to that of carnivorous mammals.
After reviewing traditional and present day concepts of the mechanism by which the external orifi... more After reviewing traditional and present day concepts of the mechanism by which the external orifice of the teat canal control the outflow of milk and the entry of bacteria etc. into the cavities of the mammary gland, this paper reports on the results of electron microscopic and other studies of the teat tip. This leads to the conclusion that the concept of a sphincter surrounding the teat canal should be substituted by one of a multi-spiralled, net-like integrated musculo-elastic system. This system may facilitate automatic closing and opening of the teat canal depending on the state of its major functional elements, namely (i) elastic fibres for passive closure under normal conditions (ii) smooth muscle fibres augmenting the former and (iii) the level of the intra-cisternal milk pressure. This closure is enhanced by soft teat canal keratin.
... Printed in Great Britain INFLUENCE OF DIET AND AGE ON CARBON ISOTOPE RATIOS IN OSTRICH EGGSHE... more ... Printed in Great Britain INFLUENCE OF DIET AND AGE ON CARBON ISOTOPE RATIOS IN OSTRICH EGGSHELL Y. VON SCHIRNDING, N. J. VAN DER MERWE Department of Archaeology, University of Cape Town, Rondebosch 7700, South Africa and J. C. VOGEL ...
South African Archaeological Bulletin, Dec 1, 1987
... Avail-able radiocarbon dates for Letaba ceramics range from the early 17th century to the 19t... more ... Avail-able radiocarbon dates for Letaba ceramics range from the early 17th century to the 19th century (Evers 1981). Two competing hypotheses have arisen as a result. ... The terraced settlement is to the south and east be-tween the track and the rocky cliffs. Page 5. ...
In the present study the bones of the skull, excluding the hyoid apparatus, are described. All th... more In the present study the bones of the skull, excluding the hyoid apparatus, are described. All the bones are aerated by sinuses. In the occipital bone the squamous part is aerated from the sinus of the parietal bone, the lateral part is aerated from the tympanic bulla and the basal part from the sinus of the basisphenoid bone. Condylar foramens and hypoglossal canals are absent. A small interparietal bone is present at birth. At an early age it fuses with the surrounding cranial bones. The squamous part of the temporal bone lies sagittally in young animals, but moves progressively to a transverse plane as the animals age. A foramen lacerum is represented by jugular and oval foramens and the carotid canal. The body of the basisphenoid bone is excavated by the massive maxillary tuberosity. The latter extends to the oval foramen and contains the developing molar teeth. The ethmoturbinate, nasal and lacrimal bones are exceptionally small. In old bulls the palatine process of the incisive bones and their sinuses are gradually displaced by the palatine process of the maxillae.
The pleural cavity of the Nile crocodile is divided into two separate cavities by means of a comp... more The pleural cavity of the Nile crocodile is divided into two separate cavities by means of a complete mediastinum. The pleural cavity contains the lungs, while the heart is situated in its own cavity, the pericardial cavity. The pleural cavity is separated from the hepatic coelom, which contains the liver, by the post-pulmonary membrane. The hepatic coelom is separated from the peritoneal cavity by the post-hepatic membrane. The peritoneal cavity contains the abdominal organs.
The dating of pigment from a South African rock painting is reported using accelerator carbon-14 ... more The dating of pigment from a South African rock painting is reported using accelerator carbon-14 counting of carbon from black pigment. Nine pigment samples of different colors from rock paintings were also chemically analyzed by quantitative microanalysis, and by energy-dispersive x-ray fluorescence. -- AATA
ABSTRACT Monthly collections of the African yellow bat, Scotophilus dinganii, were made in the Kr... more ABSTRACT Monthly collections of the African yellow bat, Scotophilus dinganii, were made in the Kruger National Park. Examination of serially sectioned reproductive tracts of females showed that the African yellow bat is a monoestrous species and that insemination, ovulation and fertilization took place during mid to late autumn (April to May). Early embryonic development of normally two embryos (one in each uterine horn) was retarded and implantation delayed until mid-winter (July), when the blastocysts implanted.
ASMOSIA 5: Interdisciplinary Studies on Ancient Stone, 2002
No single analytical technique is usually sufficient to attribute a marble object unambiguously t... more No single analytical technique is usually sufficient to attribute a marble object unambiguously to a particular quarry source in the Mediterranean world, and a number of research groups have emphasized the importance of using a multi-method approach. One exception to this rule is Cape Vathy on the island of Thasos in the northern Aegean, an important marble source in antiquity. Cape Vathy appears to have been the only significant source of dolomitic marble used in the Mediterranean region. Stable isotope analyses of classical sculptures made of dolomitic marble are all consistent with a Thasian origin, indicating that a simple, inexpensive, and essentially non-destructive "dolomite test" can be used to determine whether a marble piece is from Cape Vathy. Several hundred samples were collected from Greek and Roman statues and reliefs in museums and private collections in Europe and the United States that appeared to have been carved in marble from Cape Vathy on Thasos. X-ray diffraction (XRD) was used to test for the presence of dolomite, with the finding that 75% of the "Thasian" appearing sculptures were in fact dolomitic. Stable isotope analyses of the dolomitic sculptures have reconfirmed their Thasian attribution; these analytical data serve to further refine the isotopic field for Thasian marble and may potentially allow the identification of discrete quarry areas exploited at different times in the past. Isotopic analyses of the calcite marble sculptures add to the more than 100 analyses that we have reported at ASMOSIA III and IV. As the number of sculptures with quarry attributions grows, contributions are made to our understanding of chronological, geographic, and art historical patterns in marble use.
The malfunctioning or even absence of provincial heritage agencies in various parts of the countr... more The malfunctioning or even absence of provincial heritage agencies in various parts of the country, which are now required by the National Heritage Act, is playing havoc with plans to investigate new archaeological and palaeontological sites.
Little is known about peptide-storing endocrine cells in the gut of the Nile crocodile. As in the... more Little is known about peptide-storing endocrine cells in the gut of the Nile crocodile. As in the case of other reptiles, particularly the alligator, a limited range of peptide-storing cells was found in the gut of the crocodile. They were somatostatin, glucagon, gastrin, neurotensin and pancreatic polypeptide. The topographical distribution of cells immunoreactive to somatostatin and gastrin in the gut of the crocodile is comparable to the situation in the alligator. Glucagon and neurotensin immunoreactive cells have a much wider distribution in the gastro-intestinal tract of the crocodile compared to the alligator. Cholecystokinin and bombesin cells previously reported in the small intestine of the alligator were not detected in this study. This is the first report to demonstrate pancreatic polypeptide and serotonin immunoreactivity in the gut of a crocodilian specie.
Although the histology of the intestinal tract of Crocodylus niloticus is touched on in overall s... more Although the histology of the intestinal tract of Crocodylus niloticus is touched on in overall studies on reptilian intestinal tract, a more comprehensive light microscopical study on this area is lacking. Specimens for histological examination were taken from the duodenum, the jejunum, the ileum and the rectum. The data obtained revealed that the mucosa is thrown into folds and simple, slightly branched tubular intestinal glands. The mucosal folds diminished in height and eventually disappeared upon reaching the ileorectal junction. The epithelium covering the folds and crypts was of the simple columnar type. Clear marginal cells, goblet cells and argentaffin cells were observed throughout the intestinal tract. No Paneth cells were seen in this study. The lamina propria was rich in lymphocytic infiltrations while the muscularis mucosa consisted mainly of an outer longitudinal layer, the inner circular layer being rudimentary or absent. The submucosa was extremely narrow, and the circular and longitudinal layers of the tunica muscularis contained distinct layers of dense fibrous connective tissue. The histology of the intestinal tract of C. niloticus is shown to be in line with the situation in crocodilians and also exhibits a resemblance to that of carnivorous mammals.
After reviewing traditional and present day concepts of the mechanism by which the external orifi... more After reviewing traditional and present day concepts of the mechanism by which the external orifice of the teat canal control the outflow of milk and the entry of bacteria etc. into the cavities of the mammary gland, this paper reports on the results of electron microscopic and other studies of the teat tip. This leads to the conclusion that the concept of a sphincter surrounding the teat canal should be substituted by one of a multi-spiralled, net-like integrated musculo-elastic system. This system may facilitate automatic closing and opening of the teat canal depending on the state of its major functional elements, namely (i) elastic fibres for passive closure under normal conditions (ii) smooth muscle fibres augmenting the former and (iii) the level of the intra-cisternal milk pressure. This closure is enhanced by soft teat canal keratin.
... Printed in Great Britain INFLUENCE OF DIET AND AGE ON CARBON ISOTOPE RATIOS IN OSTRICH EGGSHE... more ... Printed in Great Britain INFLUENCE OF DIET AND AGE ON CARBON ISOTOPE RATIOS IN OSTRICH EGGSHELL Y. VON SCHIRNDING, N. J. VAN DER MERWE Department of Archaeology, University of Cape Town, Rondebosch 7700, South Africa and J. C. VOGEL ...
South African Archaeological Bulletin, Dec 1, 1987
... Avail-able radiocarbon dates for Letaba ceramics range from the early 17th century to the 19t... more ... Avail-able radiocarbon dates for Letaba ceramics range from the early 17th century to the 19th century (Evers 1981). Two competing hypotheses have arisen as a result. ... The terraced settlement is to the south and east be-tween the track and the rocky cliffs. Page 5. ...
In the present study the bones of the skull, excluding the hyoid apparatus, are described. All th... more In the present study the bones of the skull, excluding the hyoid apparatus, are described. All the bones are aerated by sinuses. In the occipital bone the squamous part is aerated from the sinus of the parietal bone, the lateral part is aerated from the tympanic bulla and the basal part from the sinus of the basisphenoid bone. Condylar foramens and hypoglossal canals are absent. A small interparietal bone is present at birth. At an early age it fuses with the surrounding cranial bones. The squamous part of the temporal bone lies sagittally in young animals, but moves progressively to a transverse plane as the animals age. A foramen lacerum is represented by jugular and oval foramens and the carotid canal. The body of the basisphenoid bone is excavated by the massive maxillary tuberosity. The latter extends to the oval foramen and contains the developing molar teeth. The ethmoturbinate, nasal and lacrimal bones are exceptionally small. In old bulls the palatine process of the incisive bones and their sinuses are gradually displaced by the palatine process of the maxillae.
The pleural cavity of the Nile crocodile is divided into two separate cavities by means of a comp... more The pleural cavity of the Nile crocodile is divided into two separate cavities by means of a complete mediastinum. The pleural cavity contains the lungs, while the heart is situated in its own cavity, the pericardial cavity. The pleural cavity is separated from the hepatic coelom, which contains the liver, by the post-pulmonary membrane. The hepatic coelom is separated from the peritoneal cavity by the post-hepatic membrane. The peritoneal cavity contains the abdominal organs.
The dating of pigment from a South African rock painting is reported using accelerator carbon-14 ... more The dating of pigment from a South African rock painting is reported using accelerator carbon-14 counting of carbon from black pigment. Nine pigment samples of different colors from rock paintings were also chemically analyzed by quantitative microanalysis, and by energy-dispersive x-ray fluorescence. -- AATA
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Papers by Nikolaas J van der Merwe
Several hundred samples were collected from Greek and Roman statues and reliefs in museums and private collections in Europe and the United States that appeared to have been carved in marble from Cape Vathy on Thasos. X-ray diffraction (XRD) was used to test for the presence of dolomite, with the finding that 75% of the "Thasian" appearing sculptures were in fact dolomitic. Stable isotope analyses of the dolomitic sculptures have reconfirmed their Thasian attribution; these analytical data serve to further refine the isotopic field for Thasian marble and may potentially allow the identification of discrete quarry areas exploited at different times in the past. Isotopic analyses of the calcite marble sculptures add to the more than 100 analyses that we have reported at ASMOSIA III and IV. As the number of sculptures with quarry attributions grows, contributions are made to our understanding of chronological, geographic, and art historical patterns in marble use.
Several hundred samples were collected from Greek and Roman statues and reliefs in museums and private collections in Europe and the United States that appeared to have been carved in marble from Cape Vathy on Thasos. X-ray diffraction (XRD) was used to test for the presence of dolomite, with the finding that 75% of the "Thasian" appearing sculptures were in fact dolomitic. Stable isotope analyses of the dolomitic sculptures have reconfirmed their Thasian attribution; these analytical data serve to further refine the isotopic field for Thasian marble and may potentially allow the identification of discrete quarry areas exploited at different times in the past. Isotopic analyses of the calcite marble sculptures add to the more than 100 analyses that we have reported at ASMOSIA III and IV. As the number of sculptures with quarry attributions grows, contributions are made to our understanding of chronological, geographic, and art historical patterns in marble use.