The taxonomy of poison ivy, with a note of the origin of the generic name,

v.4:no.3(1925)

The morphology, systematics, and evolution of the Old World treefrogs (Rhacophoridae and Hyperoliidae)

v.57(1970)

The origin of the land birds of Tristan da Cunha.

v.37:no.6(1955)

Ultrastructure of the ovary of Dermatobia hominis (Diptera: cuterebridae). II. Origin of the tunica propria in ovarioles

Ovaries up to the 8th day pupae of Dermatobia hominis were studied by transmission electron microscopy. Ovarioles were recognized in ovaries of 4-day old pre-pupae, surrounded by a thin tunica propria of acellular fibrilar material similar in structure to the internal portion of the external tunica of the ovary. There is continuity of the tunica propria and the ovarian tunica, indicating that the former structure originates from the tunica externa. In 5 to 7-day pupae the interstitial somatic cells from the apical region of the ovary, close to the ovarioles, show delicate filamentous material inside of their rough endoplasmic reticulum cisternae; similar material is seem among these cells. Our observations suggest that interstitial somatic cells do not originate the tunica propria but contribute to its final composition.

Magnetostratigraphy of the Kavaalani section (southwestern Turkey): Consequence for the origin of the Antalya Calcareous Nappes (Turkey) and for the Norian (Late Triassic) magnetic polarity timescale

A magnetostratigraphic study of the Kavaalani section of uppermost Carnian to Upper Norian age, located in the Antalya Calcareous Nappes (southwestern Turkey), reveals nineteen polarity intervals. This pattern correlates very well with two other polarity sequences obtained from the same nappe system (Bolucektasi Tepe and Kavur Tepe) if these sections were deposited in the same (northern) hemisphere. This new interpretation changes our previous conclusions regarding the southern hemisphere origin of the magnetic remanence of the Kavur Tepe section. The paleomagnetic data obtained from the Kavur Tepe and the Kavaalani sections therefore reflect large (similar to 180 degrees) internal rotations within the Antalya nappes. These nappes were likely formed close to the northern tip of the Arabian promontory. We propose a revised yet still preliminary version of the Norian magnetic polarity sequence.

Report of the Second Satellite Symposium on Ultrasound in Schistosomiasis

A group of experts on schistosomiasis and ultrasonography discussed the experiences and results obtained with the Niamey-Belo Horizonte Protocol on Ultrasonography in Schistosomiasis. A series of recomendations about qualitative and quantitative data obtained by ultrasound in studies performed in Africa and Brazil are presented. Imunological, genetic and epidemiological studies must rely on ultrasound for the identification of patients with periportal thickening/fibrosis.

Fonctions du plancher pelvien: de la phase expulsive à la consultation du post-partum [Pelvic floor functions: from the beginning of the second phase of labor to the postpartum consultation].

Vaginal delivery can cause lesions of the various pelvic structures responsible for the mechanisms of continence. These lesions may perhaps be prevented in the future by measuring pressure generated during childbirth. Tear of the anal sphincter during childbirth is a marker of a global impairment of the urinary, ano-rectal and sexual pelvic functions in the short and medium term. Persistence of a defect of the anal sphincter is frequent in spite of immediate suture. The correlation between these defects and ano-rectal incontinence are not established in our experience. The quality of the contraction of the sphincter complex and pubo-rectal sling seems to play a more important role in ano-rectal continence after a traumatic childbirth.

On the origin of the ultradeep East Barents Sea basin

Very large subsidence, with up to 20 km thick sediment layers, is observed in the East Barents Sea basin. Subsidence started in early Paleozoic, accelerated in Permo-Triassic times, finished during the middle Cretaceous, and was followed by moderate uplift in Cenozoic times. The observed gravity signal suggests that the East Barents Sea is at present in isostatic balance and indicates that a mass excess is required in the lithosphere to produce the observed large subsidence. Several origins have been proposed for the mass excess. We use 1-D thermokinematic modeling and 2-D isostatic density models of continental lithosphere to evaluate these competing hypotheses. The crustal density in 2-D thermokinematic models resulting from pressure-, temperature-, and composition-dependent phase change models is computed along transects crossing the East Barents Sea. The results indicate the following. (1) Extension can only explain the observed subsidence provided that a 10 km thick serpentinized mantle lens beneath the basin center is present. We conclude that this is unlikely given that this highly serpentinized layer should be formed below a sedimentary basin with more than 10 km of sediments and crust at least 10 km thick. (2) Phase changes in a compositionally homogeneous crust do not provide enough mass excess to explain the present-day basin geometry. (3) Phase change induced densification of a preexisting lower crustal gabbroic body, interpreted as a mafic magmatic underplate, can explain the basin geometry and observed gravity anomalies. The following model is proposed for the formation of the East Barents Sea basin: (1) Devonian rifting and extension related magmatism resulted in moderate thinning of the crust and a mafic underplate below the central basin area explaining initial late Paleozoic subsidence. (2) East-west shortening during the Permian and Triassic resulted in densification of the previously emplaced mafic underplated body and enhanced subsidence dramatically, explaining the present-day deep basin geometry.

On the origin of the Biomphalaria glabrata hemocytes

A histologic, morphometric and ultrastructural study performed on Biomphalaria glabrata submitted to infection with Schistosoma mansoni miracidia failed to provide significant evidences that the so-called amebocyte-producing organ (APO) is really the central organ for hemocyte production. In infected snails no general reactive changes appeared in the APO, the mitoses were seen only occasionally, and the possibility of cellular hyperplasia was ruled out by morphometric measurements. Under the electron microscope the APO cells presented an essentially epithelial structure, without features indicative of transition toward hemocytes. On the other hand, the present findings pointed to a multicentric origin for the mollusck hemocytes, as earlier studies had indicated. Dense foci of hemocyte collections appeared sometimes around disintegrating sporocysts and cercariae in several organs and tissues of the infected snails, including a curious accumulation of such cells inside the ventricular cavity of the heart. In the heart and other sites, features suggestive of transformation of vascular space endothelial lining cells into hemocytes were apparent. To some extent, the postulated multicentric origin for B. glabrata hemocytes recapitulates earlier embryologic findings in vertebrates, when mesenchymal vascular spaces generate the circulating and phagocytic blood cells.