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Full-Text Articles in Life Sciences
The Systematic Position Of The Avian Species Metopothrix Aurantiacus, J. Alan Feduccia
The Systematic Position Of The Avian Species Metopothrix Aurantiacus, J. Alan Feduccia
Journal of the Graduate Research Center
The Orange-fronted Softtail, Metopotlzrix aurantiacus, now known to occur in the upper Amazon in southeastern Colombia, eastern Equador, eastern Peru, western Brazil, and northeastern Bolivia (Peters, 1951: 115) was described by Sclater and Salvin (1866: 190-191), who placed it in the Pipridae. Sclater (1888: 292) retained Metopothrix in the Pipridae without comment, placing it between Masius and Pipra. Berlepsch (1903: 108), in reviewing the systemic position of the genus stated that "this bird is not a Piprine [sic] form, as was believed by its describers, but a Dendrocolaptine [sic], closely allied to Xenerpestes, and agreeing with it in general characters …
Adrenal Corticosteroidogenesis And Hypothyroidsm: Effect Of Long-Term Treatment With P-Aminobenzoic Acid, John L. Mccarthy, Linda W. Laury
Adrenal Corticosteroidogenesis And Hypothyroidsm: Effect Of Long-Term Treatment With P-Aminobenzoic Acid, John L. Mccarthy, Linda W. Laury
Journal of the Graduate Research Center
The relationship between induced hypothyroidism and adrenal involution has been studied by a variety of approaches in an attempt to elucidate the physiological basis between the events. McCarthy et al. (1959) reported on an investigation of feeding several antithyroidal agents to rats to study adrenal gland involution. While adrenal involution did occur following treatment with several of the goitrogens, only in one case was there a difference in peripheral plasma adrenal corticoid levels. In rats fed p-aminobenzoic acid (PABA) for 12 weeks, peripheral levels of corticosterone (B) decreased and levels of a Porter-Silber positive chromogen increased markedly. Work from the …
Preface, Joe P. Harris
Preface, Joe P. Harris
Journal of the Graduate Research Center
When classes started in the Fall, 1969, at Southern Methodist University, it was the first time in forty-two years that Mayne Longnecker was not present to greet the new students on campus.
Natural History Of The Avian Families Dendrocolaptidae (Woodhewers) And Furnariiae (Ovenbirds), J. Alan Feduccia
Natural History Of The Avian Families Dendrocolaptidae (Woodhewers) And Furnariiae (Ovenbirds), J. Alan Feduccia
Journal of the Graduate Research Center
During my investigations of the evolution of the woodhewers and ovenbirds I attempted to gather together data on the natural history of the groups and synthesize it into a meaningful form. In this summary I have stressed habitat, food, foraging behavior, and nidification. Although it should be realized that the present generic limits (Peters, 1951) are at best tentative, I thought it best to summarize the natural history according to the present classification. As most of the future changes in the classification of these groups will very likely involve lumping of genera, the information contained herein should remain separable to …
Fine Structure Of The Fibrillar Flight Muscles In The Housefly, Musca Domestica (Diptera), R. S. Sohal, V. F. Allison
Fine Structure Of The Fibrillar Flight Muscles In The Housefly, Musca Domestica (Diptera), R. S. Sohal, V. F. Allison
Journal of the Graduate Research Center
Insects of the orders Hemiptera, Hymenoptera, Coleoptera and Diptera have developed an asynchronous flight mechanism. The frequency of the muscle contraction is not directly related to the rate of nervous stimulation (Pringle 1965). An initial nervous stimulus produces an active state in the flight muscle during which a variable number of oscillatory contractions take place. Consequently, insects like the house-fly can maintain a very high frequency of wing beat (180-200 per second). Asynchronous flight muscles differ from the vertebrate skeletal muscles and insect synchronous flight muscles; in the latter each nerve impulse produces a single contraction of the innervated fibres. …
A New Shorebird From The Upper Pliocene, J. Alan Feduccia
A New Shorebird From The Upper Pliocene, J. Alan Feduccia
Journal of the Graduate Research Center
One of the avian fossils recovered from the Saw Rock Canyon local fauna of the Upper Pliocene of Seward County, Kansas, is the humerus of a scolopacine shorebird which closely resembles the Recent Tringa solitaria. Present evidence favors a late Hemphillian age for the fauna (Hibbard, 1964. Pap. Michigan Acad. Sci., Arts, and Letters, 49: 115-127), and the fauna is taken from a lower section of the Rexroad formation than are the Fox Canyon and Rexroad local faunas of the Rexroad formation of Meade County, Kansas. Many of the mammals in the Saw Rock Canyon local fauna are considered to …
Fine Structure Of Nucleoli In Cells Of Encysted Hymenolepis Diminuta, John E. Ubelaker
Fine Structure Of Nucleoli In Cells Of Encysted Hymenolepis Diminuta, John E. Ubelaker
Journal of the Graduate Research Center
Studies of the fine structure of 5 day old cysticercoids of H. diminuta revealed nucleoli with well-formed lamellae in germinal cells within the body of the encysted worm. The nucleoli were located centrally in the nucleus and appeared not to be attached to the chromosomes, chromatin, or to the nuclear envelope.
Evidences Of Diurnal Feeding Activity In Trichoptera Larvae, John O. Mecom
Evidences Of Diurnal Feeding Activity In Trichoptera Larvae, John O. Mecom
Journal of the Graduate Research Center
The literature of the aquatic insect order Trichoptera (caddisflies) is extensive. Ross (1944), Denning (1950a, 1950b, 1954, 1956), Banks (1944) and Betten (1934), among others, have been major contributors to the taxonomy and zoogeography of North American species. Important studies of the general ecology of both adult and larval forms have been made by Lloyd (1921), Scott (1958), and Hynes (1961) but Mecom and Cummins (1964) have commented on the limited knowledge of the trophic relationships of Trichoptera. Hanna (1957), Jones (1950), Chapman and Demory (1963) studied the food ingested by Trichoptera larvae, but except for the very limited experiments …
Dialysis Studies Of The K+ Binding Capacity Of Physarum Polycephalum, Claude Nations
Dialysis Studies Of The K+ Binding Capacity Of Physarum Polycephalum, Claude Nations
Journal of the Graduate Research Center
Anderson (1964) has observed that migrating plasmodia of the slime mold, Physarum polycephalum, maintain a higher concentration of K+ in the region of the advancing front than in the posterior trailing region. He has also found that most of the Na- but little of the K+ in the posterior region can be removed by flushing water over the organism. Previous work by Anderson (1962) had revealed that alcohol precipitates prepared from plasmodial homogenates contain considerable quantities of K- which cannot be removed by washing. Based on these discoveries he has suggested that K+, but not Na+ is closely associated with …
Morphological Variation In Cephalogonimus Americanus (Trematoda: Cephalogonimidae) From Amphibians In Colorado, John E. Ubelaker, John D. Kimbrough
Morphological Variation In Cephalogonimus Americanus (Trematoda: Cephalogonimidae) From Amphibians In Colorado, John E. Ubelaker, John D. Kimbrough
Journal of the Graduate Research Center
A collection of western toads, Bufo boreas Baird and Girard, 1852, and neotenic tiger salamanders, Ambystoma tigrinum (Green) from Sheep Lake, Horseshoe Park, Rocky Mountain National Park, Colorado, were examined for helminths in the spring of 1966. Oswaldo-Cruzia subauricularis (Rudolphi, 1819) was found in Bufo boreas and Ophiotaenia filarioides (LaRue, 1909) in Ambystoma tigrinum. In addition, both hosts harbored Spironoura pretiosa Ingles, 1936, Phylloclistomum bufonis Frandsen, 1957 and Cephalogonimus americanus. The last species differed greatly in appearance in the two hosts and these differences are reported herein.