mechanisms of chromosome banding. ix. are variations in dna base composition adequate to account for quinacrine, hoechst 33258 and daunomycin banding?prior studies on subfractions of mouse and kangaroo rat dna have suggested that variations in base concentration within a given genome may not be great enough to account for q-banding. to examine this with another species, calf dna was subfractionated by cscl ultracentrifugation into gc-rich satellites and the main band dna was further fractionated into at-rich, intermediate and gc-rich portions. the effect of varying concentrations of these dnas on quinacrine and hoechst 33258 fluorescence was ...197661106
binding of anti-nucleoside antibodies reveals different classes of dna in the chromosomes of the kangaroo rat (dipodomys ordii). 197770368
measurements on the kidneys and vasa recta of various mammals in relation to urine concentrating capacity.maximum urine-concentrating capacity (ucc) differs widely among mammals of different species, being very high in some desert species (e.g. kangaroo rats) and very low in freshwater acquatic species (e.g. beaver). in this study, kidneys of 21 species of mammals from widely different habitats were studied in histological sections to determine whether differences in ucc can be attributed to differences in kidney structure. parameters studied included the ratio of medullary to cortical thickness, th ...1977407772
mechanical vs. ischemic mechanisms for decompression sickness.we used 20 kangaroo rats to investigate the effect of exposure to low oxygen levels (0.11 atm 02 inspired partial pressure) prior to decompression from a steady-state condition. this hypoxia was found to afford significant protection against limb bends as simulated in those animals by tail biting. yet, it potentiated neurologic symptoms compared with a control exposure on air with the same level of nitrogen supersaturation. however the incidence of simulated limb bends in the same animals was th ...1979464957
an anatomical study of the brains of dipodomys (mammalia: rodentia: heteromyidae).whole brains and nissl-stained serial sections of 3 species of kangaroo rat (dipodomys spectabilis, d. ordii, d. merriami) were compared for interspecific differences. neuroanatomical variations were conservative in nature. examination of the cerebellum revealed possible differences in locomotion and ecology. dipodomys ordii exhibited more neurological evidence for increased specialization of the hindlimbs, while d. merriami had the least differentiated cerebellar surface, thereby suggesting mor ...1979507367
water balance of merriam's kangaroo rat, dipodomys merriami, during cold exposure. 1975237660
some comparative aspects of renal adaptation to unilateral nephrectomy in white rats and kangaroo rats. 1975236118
preferential occurrence of sister chromatid exchanges at heterochromatin-euchromatin junctions in the wallaby and hamster chromosomes.chromosomes of two mammalian species, the white-throated wallaby and the rat-like hamster, possessed large amounts of constitutive heterochromatin which is detectable as c bands. by making use of this character the frequency of sister chromatid exchanges (sces) was determined for the c band and the euchromatic regions of the chromosome. in both species, the distribution of sces in the euchromatin of chromosomes was found to be proportional to its metaphase length, while the number of sces locali ...1979510085
wheel running of kangaroo rats, dipodomys merriami, as related to food deprivation and body composition.kangaroo rats deprived of food ran themselves to death in 48 h in wheel cages. despite the loss of 14.5% of body weight the ratio of water to protein was the same after the run as it was in control rats. metabolic measurements at rest and in the running wheel and weight loss in the 48-h run were used to estimate fuels used and water expended. two-thirds of the initial amount of fat and 9% of the protein were metabolized. the terminal mean percentage of body fat was about twice that observed in r ...1978627494
dipodomydectes americanus gen. et sp. n. (acari: hypoderidae) from the kangaroo rat. 1978627953
similarity of satilite dna properties in the order rodentia.we have characterized satellite dnas from 9 species of kangaroo rat (dipodomys) and have shown that the hs-alpha and hs-beta satellites, where present, are nearly identical in all species as to melting transition midpoint (tm), and density in neutral cscl, alkaline cscl, and cs(2)so(4)-ag(+) gradients. however, the ms satellites exist in two internally similar classes. the satellite dnas from three other rodents were characterized (densities listed are in neutral cscl). the pocket gopher, thomom ...1977561953
the kangaroo rat as a model for type i decompression sickness.this study involved 720 exposures of 70 kangaroo rats trapped in west texas and showed that decompression-induced tail biting in this animal provides a good animal model for marginal limb bends in man. that this phenomenon can be reversed by recompression and pathological examination of the tail both indicated that a similar mechanism is probably involved in kangaroo rats and humans. quantitatively, the most susceptible 20% of kangaroo rats can reproduce the no-stop decompression limits for man ...1978734799
[sleep in marsupio, the kangaroo rat (potorous apicalis)]. 1978693605
nucleotide sequences of hs-alpha satellite dna from kangaroo rat dipodomys ordii and characterization of similar sequences in other rodents. 1977597857
response characteristics of cochlear nucleus neurons to vowel sounds.most studies in auditory neurophysiology have utilized tonal stimuli to determine the coding properties of neurons in the cochlear nuclei. in this investigation of the kangaroo rat, cochlear nuclei, neuronal responses to vowel sounds, as well as tones, were studied. the vowel sounds, each about 40 msec in duration were: see article. five were linked together to form a 200 msec stimulus and various combinations of five vowel sounds provided us with 18 different stimuli. the results show that neur ...1977835971
fine structure of the heterochromatin of the kangaroo rat dipidomys ordii, and examination of the possible role of actin and myosin in heterochromatin condensation.biochemical studies have suggested that some actin and myosin may be present in the nucleus. this raises the possibility that heterochromatin condensation might be the result of an actin-myosin rigour type complex. since atp dissociates actin and myosin, this possibility could be examined by determining the effect of atp on heterochromatin condensation. thin-section electron microscopy showed large amounts of condensed constitutive heterochromatin in the kidney nuclei and somewhat less in the li ...1976823163
the pineal complex and its relationship to other epithalamic structures.the pineal complex of rodents is made up of a pineal gland which developmentally always originates from the area between the habenular and posterior commissure and a pineal sac which is continuous with the choroid plexus of the third ventricle. at the light-microscopic level, this sac appears to be identical to the choroid plexus. the pineal sac abuts the deep and superficial pineal glands of the golden hamster. in the pet mouse, gerbil, kangaroo rat, and chinese hamster, the sac is contiguous w ...1977899706
kangaroo rat cochlea: qualitatively and quantitatively unique features. 1977898499
an analysis of sandbathing and grooming in the kangaroo rat (dipodomys merriami).the sandbathing and grooming behaviour of ten kangaroo rats (dipodomys merriami) were recorded on sand and woodchip substrates after periods of 0, 1, 5 and 10 days without sand. sandbathing is restricted to the sandy substrate. grooming occurs on both, but with a higher frequency on sand. increases in both grooming and sandbathing occur with increasing sand deprivation, but the temporal patterning does not change. d. merriami tends to alternate sandbathing components in contrast to other dipodom ...1976937766
analysis of the frequency of sister chromatid exchange in different regions of chromosomes of the kangaroo rat (dipodomys ordii).the frequency of sister chromatid exchanges (sces) has been determined for c band and non-c band regions of chromosomes of the kangaroo rat after staining with the fluorescence plus giemsa (fpg) technique. after one complete round of dna synthesis in the presence of bromodeoxyuridine (brdu) staining of the c band regions revealed simple or complex asymmetries between chromatids. after two complete rounds of dna synthesis in the presence of brdu "harlequin" chromosomes were observed. analysis of ...1976964105
central nervous regulation of body temperature during sleep.the relationship between hypothalamic temperature and metabolic heat production was measured during wakefulness, slow-wave sleep, and paradoxical sleep in unrestrained kangaroo rats (dipodomys). hypothalamic temperature was manipulated with chronically implanted, water-perfused thermodes while cortical electroencephalogram, electromyogram, metabolic rate, and body movement were continuously recorded. during slow-wave sleep, in comparison to wakefulness, there is a lowered threshold hypothalamic ...1976973138
[the ontogenesis of nycthemeral rhythm of the states of sleep in the kangaroo rat (potorous apicalis) (author's transl)]. 1976996149
s phase patterns of replication of different satellite dnas in three species of dipodomys (kangaroo rat). 19761011258
investigation of the organization of mammalian chromosomes at the dna sequence developments in dna sequencing techniques permit rapid progress in the determination of both repetitious and single-copy mammalian sequences. three distinct families of highly repetitious satellite dna's from the kangaroo rat dipodomys ordii have been sequenced. with the ms satellite it was possible to show that the basic repeat sequence and its variants were arranged in a nonrandom order suggesting a hierarchy of repeats. the hs-alpha satellite from d. ordii was shown to resemble the guinea ...19761107072
food-deprivation-induced polydipsia in two species of kangaroo rats. 19751144612
wood rats and kangaroo rats: potential reservoirs of the lyme disease spirochete in california.the etiologic agent of lyme disease, borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner, was isolated repeatedly from dusky-footed wood rats, neotoma fuscipes baird, and california kangaroo rats, dipodomys californicus merriam, in northern california. all animals were collected in a region endemic for lyme disease but for which the natural reservoir of b. burgdorferi was unknown. similar attempts to isolate spirochetes from lizards, other species of rodents, jack rabbits, and deer ...19911875357
auditory systems of heteromyidae: postnatal development of the ear of dipodomys merriami.serial histological sections of kangaroo rats of postnatal ages 0-, 3-, 7-, 10-, and 14-days were prepared and studied. at birth the middle ear is mostly filled with mesenchyme and small in size, having only a small hypotympanum and a very small epitympanic recess. during the first postnatal two weeks, much of the hypertrophy found in the adult middle ear develops. because an entotympanic element is nev er formed, the previously called entotympanic chamber is here renamed the hypotympanum. the e ...19751142445
spatial memory and adaptive specialization of the hippocampus.the hippocampus plays an important role in spatial memory and spatial cognition in birds and mammals. natural selection, sexual selection and artificial selection have resulted in an increase in the size of the hippocampus in a remarkably diverse group of animals that rely on spatial abilities to solve ecologically important problems. food-storing birds remember the locations of large numbers of scattered caches. polygynous male voles traverse large home ranges in search of mates. kangaroo rats ...19921384199
parasitic and phoretic arthropods of the elephant-eared and the santa cruz kangaroo rats.the parasitic and phoretic arthropods of the elephant-eared kangaroo rat (dipodomys elephantinus) and santa cruz kangaroo rat (d. venustus) are reported; most of these represent new host records. thirteen of 14 (93%) of d. elephantinus and 11 of 12 (92%) of d. venustus had 11 and nine arthropod species, respectively. larval and nymphal stages of the tick dermacentor occidentalis were the most prevalent parasite (77%) on d. elephantinus whereas the mesostigmatid mite androlaelaps fahrenholzi was ...19912067062
spatial and temporal continuity of kangaroo rat populations shown by sequencing mitochondrial dna from museum specimens.the advent of direct sequencing via the polymerase chain reaction (pcr) has opened up the possibility of molecular studies on museum specimens. here we analyze genetic variation in populations over time by applying pcr to dna extracted from museum specimens sampled from populations of one species over the last 78 years. included in this study were 43 museum specimens of the panamint kangaroo rat dipodomys panamintinus from localities representing each of three geographically distinct subspecies. ...19902120448
chromosomes of a cell line of dipodomys panamintinus (kangaroo rat). a banding and autoradiographic study.the chromosomes of an established cell line of dipodomys panamintinus have been characterised in terms of their c, g and q banding patterns, and the distributions of silver grains in autoradiographs of chromosomes labelled in early or late s phase. no relationship could be established between c, g or q banding regions of chromosomes and a particular s phase time of replication of the dna in these banded regions. the implication of this result to the concept of heterochromatin is discussed.197549259
consumption and mortality of the white-footed mouse (rodentia: muridae) and ord's kangaroo rat (rodentia: heteromyidae) when fed carbaryl-bran grasshopper (orthoptera) bait.two species of wild rodents (ord's kangaroo rat, dipodomys ordii woodhouse, and the white-footed mouse, peromyscus leucopus rafinesque) were fed 0, 2, and 20% (ai) by weight concentrations of carbaryl-bran grasshopper bait in the laboratory to determine whether the bait would be consumed, the total quantity of bait consumed within a specified period, whether mortality would occur, and whether bait would be consumed if other foods were readily available. consumption tests showed that bait ingesti ...19902126269
the effects of delta-9-tetrahydrocannabinol on actin microfilaments.fluorescence staining with rhodamine phalloidin specific for f-actin was employed to examine the effects of delta-9-tetrahydrocannabinol (thc) on the distribution of microfilaments in kangaroo rat epithelial cells (ptk2) and rabbit aortic endothelial cells (rae). ptk2 cells were more sensitive to thc treatment than rae cells. exposure of ptk2 cells to 10 microm thc for 2 h disrupted the microfilament network. after treatment with 20 microm thc for 2 h there was a loss of cell-to-cell contact bet ...19902175259
the sequence of the 3.3-kilobase repetitive element from dipodomys ordii suggests a mechanism for its amplification and interspersion.dna from the kangaroo rat, dipodomys ordii, contains a 3.3-kb, highly repeated sequence that is interspersed throughout the genome in small tandem clusters. one 3.3-kb unit has been cloned into pbr322 and the nucleotide sequence determined. the clone used was shown to be representative of the bulk of such sequences found in the genomic dna. the sequence contains 10 homologous subunits each ca. 260 bp in length. comparison of these to one another yielded a 258-bp consensus sequence containing a 3 ...19873041011
preferred speeds in terrestrial vertebrates: are they equivalent?terrestrial animals have 'preferred speeds' within each gait, that are used much more frequently than others for moving along the ground. energy costs reach minimal values at these speeds within each gait. in this study we asked whether these speeds are mechanically equivalent among different animals (i.e. speeds where the same levels of peak muscle stress occur). if so, this would help in establishing a link between the energetics and the mechanics of the active muscles at these speeds, providi ...19883209967
effects of a low op dose on seed/bead discrimination in the kangaroo rat, dipodomys. 19892758144
radionuclide transport from soil to air, native vegetation, kangaroo rats and grazing cattle on the nevada test site.between 1970 and 1986 the nevada applied ecology group (naeg), u.s. department of energy, conducted environmental radionuclide studies at weapons-testing sites on or adjacent to the nevada test site. in this paper, naeg studies conducted at two nuclear (fission) sites (ns201, ns219) and two nonnuclear (nonfission) sites (area 13 [project 57] and clean slate 2) are reviewed, synthesized and compared regarding (1) soil particle-size distribution and physical-chemical characteristics of 239 + 240pu ...19883198397
genomic structure and sequence variation of a 3.3-kb repeat dna element of the kangaroo rat, dipodomys ordii.the genomic structure and sequence variation of a 3.3-kb repeat dna element, representing 5% of the genome of the kangaroo rat dipodomys ordii, has been investigated. most of the repeats are arranged in tandem arrays of 50 kb or more. thirteen randomly selected genomic clones have been mapped with twelve restriction enzymes. the frequency of sequence divergence in the genomic clones is 0.5%. the clone maps and the genomic structure studies have permitted the characterization of a number of varia ...19883215518
[effect of cultivation conditions on the karyotype structure of a cell subline of the kangaroo rat kidney].variations in cultivation conditions were found to exert influence on the distribution of cells for chromosome number by changing the modal class. the change of the hmem medium for the emem medium during 2-6 passages results in the appearance of a new modal class with 16 chromosomes. the change in the chromosome number is preferably due to the loss of one x chromosome within the main structural variant of the karyotype (msvk). on the other hand, the change of the hmem medium for the f12 medium d ...19883245098
vertical distribution of soil removed by four species of burrowing rodents in disturbed and undisturbed soils.burrow volumes were determined in disturbed and undisturbed soils for four species of rodents in southeastern idaho. comparisons were made between soil types for the average volume and the proportion of the total volume of soil excavated from 10-cm increments for each species, and the relative number of burrows and proportion of total soil removed from beneath the minimum thickness of soil covers over buried low-level radioactive wastes. burrows of montane voles (microtus montanus) and deer mice ...19883280518
hearing in two cricetid rodents: wood rat (neotoma floridana) and grasshopper mouse (onychomys leucogaster).the audiograms of two wood rats and three grasshopper mice were determined with a conditioned avoidance procedure. the wood rats were able to hear tones from 940 hz to 56 khz at a level of 60 db (spl), with their best sensitivity of -3 db occurring at 8 khz. the hearing of the grasshopper mice ranged from 1.85 khz to 69 khz at 60 db (spl), with their best sensitivity of 9 db also occurring at 8 khz. these results support the relation between interaural distance and high-frequency hearing and bet ...19853899497
lack of gonadal control of the dorsal gland and sandbathing in male and female bannertail kangaroo rats, (dipodomys spectabilis).previous studies have demonstrated gonadal control of mammalian scent glands; castration leads to reduced scent-marking rates and smaller gland sizes. i investigated whether gonadal hormones control the size of the dorsal gland (a specialized sebaceous gland) and sandbathing as a scent-marking behavior in adult male and female bannertail kangaroo rats (dipodomys spectabilis). gland sizes of males and females were similar in all age classes, except adult males with larger body weights had proport ...19863957263
thermoregulatory responses to photoperiod by kangaroo rats (dipodomys ordii): influence of night lighting on nonshivering thermogenesis and resting metabolism.the influence of photoperiod on resting oxygen consumption and nonshivering thermogenesis of winter-acclimatized kangaroo rats was determined by exposing freshly captured animals to 10-week controlled photoperiod treatments. three treatments were employed: 1) long days (ld) = 16l:8d, 2) short days (sd) = 8l:16d, and 3) short days interrupted with 15 min light at midnight (sdl). thermoneutral oxygen consumption was uninfluenced by treatment, and posttreatment values were not different from pretre ...19854056675
helminths of sympatric populations of kangaroo rats (dipodomys ordii) and grasshopper mice (onychomys leucogaster) from the high plains of eastern new mexico.during a 1-yr period 124 dipodomys ordii and 92 onychomys leucogaster were trapped from the same locality and were examined for helminths. only 1 cestode species (catenotaenia linsdalei) was recovered from d. ordii, whereas o. leucogaster was infected with 2 nematoda (litomosoides carinii, mastophorus muris), 2 cestoda (hymenolepis citelli, and 1 unknown), and 1 acanthocephalan (moniliformis clarki) species. all represent new host and distribution records.19854057002
coccidia from california kangaroo rats (dipodomys spp.). 19854057012
responses of merriam's kangaroo rats, dipodomys merriami, to various levels of carbon dioxide concentration. 19734145439
physiological and ecological studies on the chisel-toothed kangaroo rat, dipodomys microps. 19734145768
timing of replication of the satellite and main band dnas in cells of the kangaroo rat (dipodomys ordii). 19724117038
location of satellite dnas in the chromosomes of the kangaroo rat (dipodomys ordii). 19734125443
autoradiographic studies of the replication of satellite dna in the kangaroo rat. autoradiographs of satellite dna. 19744280447
histo-pathological changes in cold-exposed kangaroo rats, dipodomys merriami. 19714397890
energy metabolism and body water turnover rates of two species of free-living kangaroo rats, dipodomys merriami and dipodomys microps. 19714397891
blood composition in normothermic and hyperthermic kangaroo rats dipodomys merriami and laboratory rats rattus norvegicus. 19724405342
[sleep in the kangaroo rat (potorous apicalis). a study in the adult and in the young one month before final leaving of the pouch. effects of weaning]. 19744138249
central auditory system of the kangaroo rat, dipodomys merriami. 19684185131
ultrastructural changes in the neural lobe of the hypophysis of the kangaroo rat (dipodomys merriami) following intraperitoneal injection of hypertonic sodium chloride. 19694185961
a possible relationship between satellite dna and the evolution of kangaroo rat species (genus dipodomys). 19724509020
importance of green vegetation for reproduction in the kangaroo rat, dipodomys merriami merriami. 19734706256
histochemical observations on placentation of the kangaroo rat (dipodomys) with special reference to the trophospongium and giant cells. 19734731810
nucleotide sequence of hs-beta satellite dna from kangaroo rat dipodomys ordii.the sequence of the highly repetitive satellite hs-beta dna fraction from kangaroo rat dipodomys ordii was determined independently by rna and dna sequencing techniques. a basic iterated sequence of 10 nucleotides with several mutational variations was found. base-composition data are consistent with the proposed sequence and revealed a high content of 5-methylcytosine. dna and rna sequencing techniques used gave identical results, showing that the fidelity of synthesis of riboguanidine-substitu ...19734517675
implications of karyotypic variation in the kangaroo rat, dipodomys heermanni. 19734761364
biological half-life studies of tritium in chronically exposed kangaroo rats. 19725025235
nutrition requirements of the kangaroo rat (dipodomys ordii) as indicated by dietary self-selection. 19725035252
effect of running on water balance of the kangaroo rat. 19725022381
seasonal variation in moonlight avoidance by bannertail kangaroo rats. 19744819590
vocalization in merriam's kangaroo rat. 19744833191
kangaroo rat auditory thresholds before and after middle ear reduction. 19725072747
classification of subpopulations of neurons in the cochlear nuclei of the kangaroo rat. 19725077556
histocytochemical pattern of enzyme distribution in cochlea of the kangaroo rat (d. spectabilis) at rest and following auditory stimulation. 19715095494
a model of respiratory heat transfer in a small mammal.a steady-state model of the heat and water transfer occurring in the upper respiratory tract of the kangaroo rat, dipodomys spectabilis, is developed and tested. the model is described by a steady-state energy balance equation in which the rate of energy transfer from a liquid stream (representing the flow of heat and blood from the body core to the nasal region) is equated with the rate of energy transfer by thermal conduction from the nose tip to the environment. all of the variables in the eq ...19715113001
muscle forces during locomotion in kangaroo rats: force platform and tendon buckle measurements compared.the muscle forces and stresses occurring during normal locomotor activity in kangaroo rats are compared with the peak isometric force developed by the same muscles in situ. two methods were used simultaneously to determine the stresses (force/cross-sectional area) acting in the ankle extensors during steady-speed hopping and during jumps when animals were startled: a direct measurement using a force buckle surgically implanted around a tendon; and an indirect measurement using a force platform/c ...19883209966
characteristic delay neurons in the inferior colliculus of the kangaroo rat. 19715110223
kangaroo rat locomotion: design for elastic energy storage or acceleration?mechanical stresses (force/cross-sectional area) acting in muscles, tendons and bones of the hindlimbs of kangaroo rats (dipodomys spectabilis) were calculated during steady-speed hops and vertical jumps. stresses were determined from both high-speed ciné films (light and x-ray) and force plate recordings, as well as from in vivo tendon force recordings. stresses in each hindlimb support element during hopping (1.6-3.1 m s-1) were generally only 33% of those acting during jumping (greater than o ...19883204333
development and evolution of the carotid circulation in geomyoid rodents in relationship to their craniomorphology.the diversity in cranial morphology of living geomyoids, including pocket gophers (thomomys), spiny pocket mice (heteromys and liomys), desert pocket mice (chaetodipus and perognathus), and kangaroo rats and mice (dipodomys and microdipodops) is accompanied by only a few differences in their cephalic arterial circulation. the principal difference is the origin of the pterygopalatine artery, which serves the orbit and rostrum. in dipodomyines and perognathines it originates as a stapedial branch ...19902338717
the fine structure of the trophospongial layer of the kangaroo rat placenta.the trophospongial layer of the near-term kangaroo rat placenta was examined in the electron microscope. two ultrastructurally different cellular zones were distinguishable - an inner zone adjacent to the labyrinth and a basal zone located mesometrial to the inner zone. inner zone cells contained a well developed granular er and golgi apparatus as well as polymorphous membrane-limited granules. the cells also contained modest amounts of glycogen and lipid droplets. basal zone cells were also ric ...19751200411
projection of the cochlea to cochlear nuclei in merriam's kangaroo rat. 19715134323
regulation of plasma antidiuretic hormone in the dehydrated kangaroo rat (dipodomys spectabilis m.).a sensitive and specific radioimmunoassay was used to measure plasma antidiuretic hormone (plasma arginine vasopressin, pavp) concentrations in a conscious desert-adapted mammal, the banner-tailed kangaroo rat (dipodomys spectabilis; 131 +/- 2.3 g body mass), during normal hydration and in response to progressive dehydration. simultaneous measurements of pavp and plasma osmolality (posm) in these experiments permitted determination of the hypothalamo-neurohypophyseal system-osmoreceptor set poin ...19883360285
intrinsic innervation of the urinary bladder of kangaroo and albino rats.a comparative study of the intrinsic innervation in desert rodents (kangaroo rats) and others (albino rats) was carried out in an attempt to understand the functional anatomy of the bladder in these animals which are known to sustain severe water restraint. the bladder of the albino rat was innervated by predominantly thin nerves, more numerous beaded endings and few ganglia. that of the kangaroo rat had more numerous thick nerves (pre-ganglionic), large verve trunks, and ganglia which were exte ...19751155000
projections of the trapezoid body and the superior olivary complex of the kangaroo rat (dipodomys merriami).glass micropipettes filled with 2 m sodium cyanide were used to physiologically locate and iontophoretically damage the nucleus of the trapezoid body (ntb), the medial superior olive (mso), and the lateral superior olive (lso). mechanical lesions were made in the trapezoid body as it leaves the cochlear nuclei. after a 3- to 10-day survival time the projections and terminal degeneration were traced with the fink-heimer and nauta-gygax stains. the ventral cochlear nucleus (vcn) projects via the t ...19751192176
the endogenous stages of eimeria utahensis (protozoa: eimeriidae) in the kangaroo rat, dipodomys ordii.the endogenous life cycle of eimeria utahensis is described from experimentally infected kangaroo rats, dipodomys ordii. the endogenous asexual cycle consisted of 4 generations of meronts. first-generation meronts were concentrated in the anterior third of the small intestine. the succeeding generations of meronts and the sexual stages were concentrated in the middle third of the small intestine. first-generation meronts had a mean diameter of 9.7 micrometer and contained 12 to 16 merozoites. se ...1978627970
functional characteristics of superior olivary neurons to binaural stimuli.this investigation was undertaken to study the timing properties of low-frequency binaural neurons located in the medulla of kangaroo rat (dipodomys spectabilis). the results show that the response variables, vector strength (vs) and discharge rate (dr), are not necessarily related responses; each may be conveying a different parameter of acoustic stimuli. the results also lead to the conclusion that binaural low-frequency neurons, whether they are excitatory-excitatory (ee) or excitatory-inhibi ...19751177003
[karyological characteristics of cell sublines of the kidney of the kangaroo rat and of skin fibroblasts of the indian muntjac].a study was made of the karyotypic structure of sublines derived from the kangaroo rat's kidney (nbl-3) and skin fibroblasts of the indian muntjac, available in the cell culture bank of the institute of cytology acad. sci. ussr. a comparative karyologic analysis was made of subline nbl-3 both contaminated with mycoplasma (nblk) and decontaminated with antibiotics (nbld). authentic differences in cell distribution according to chromosome number in nblk and nbld variants were shown. modal numbers ...19883176180
influence of hypothalamic and ambient temperatures on sleep in kangaroo rats.unanesthetized, unrestrained kangaroo rats (dipodomys) were studied to examine the changes in the frequency and duration of sleep states caused by long-term manipulations of hypothalamic temperature (thy) at a thermoneutral (30 degrees c) and a low (20 degrees c) ambient temperature (ta). a cold stimulus present in either the hypothalamus or the skin decreased both the total sleep time (tst) and the ratio of paradoxical sleep (ps) to tst. at a low ta, tst, but not the ps-to-tst ratio, was increa ...1979223451
cns regulation of metabolic rate in the kangaroo rat dipodomys ingens.water-perfused thermodes were chronically implanted around the preoptic nuclei and hypothalamus (poh) of kangaroo rats (dipodomys ingens). responses in rate of metabolic heat production to manipulations of poh temperature (thy) were measured in unanesthetized, unrestrained animals at ambient temperatures of 10, 20, 25, and 30 degreec. the threshold thy and the proportionally constant (alpha) for this response consistently decreased as ambient temperature increased, but alpha was not significan ...1975168786
satellite dna and cytogenetic evolution. dna quantity, satellite dna and karyotypic variations in kangaroo rats (genus dipodomys).the genus dipodomys (kangaroo rats) exhibits major interspecies variations in the proportions of highly reiterated satellite dna sequences in the genome as well as in the chromosome number and the proportions of uni-armed and bi-armed chromosomes. for nearly all of the approximately 22 species of the genus and several subspecies, liver dna was distributed in neutral cscl buoyant density gradients into four fractions; principal dna (1.698 g/ml), intermediate-density dna (1.702 g/ml), ms satellite ...19761001153
ascending and descending projections of the inferior colliculus in the kangaroo rat (dipodomys merriami). 19715148388
karyotypes of the panamint kangaroo rat (dipodomys panamintinus (merriam)). 19715144880
organ weights and serum total cholesterol in the kangaroo rat (dipodomys merriami). 19695351971
daily cycles of hibernation in the kangaroo rat, dipodomys merriami. 19715156357
adaptive value of hearing and vision in kangaroo rat predator avoidance. 19715165734
evaporative water loss and gross effects of water privation in the kangaroo rat, dipodomys venustus. 19695373855
neuronal responses of kangaroo rat ventral cochlear nucleus to low-frequency tones. 19705411028
ecology and radiation exposure of kangaroo rats living in a tritiated environment. 19705473402
response diversity of neurons in ventral cochlear nucleus of kangaroo rat to low-frequency tones. 19705439342
intranuclear distribution of satellite dna from kangaroo rat. 19705490345
satellite dna's in the kangaroo rat. 19705490264
karyotypes of kangaroo rats from southern california. 19715545558
preferential loss of kangaroo chromosomes in hybrids between chinese hamster and kangaroo-rat somatic cells. 19705531375
hematopathologic surveys of kangaroo rats (dipodomys microps) populating plutonium contaminated regions of the nevada test site. 19685688316
energy expenditure of running kangaroo rats dipodomys merriami. 19705515607
Displaying items 1 - 100 of 284