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stroop-like interference in the real animal size test and the pictorial animal size test in 5- to 12-year-old children and young adults.this study examined prepotent response inhibition among 653 5- to 12-year-old children and young adults divided into five age groups: forty-six 5- to 6-year-olds, one hundred fifty-eight 7- to 8-year-olds, one hundred ninety-six 9- to 10-year-olds, one hundred eighty-three 11- to 12-year-olds, and 70 young adults (19- to 22-year-olds). two paper-and-pencil versions of stroop-like tasks were administered: the real animal size test and the pictorial animal size test. in these tests, participants a ...201424716870
exaggerated trait allometry, compensation and trade-offs in the new zealand giraffe weevil (lasiorhynchus barbicornis).sexual selection has driven the evolution of exaggerated traits among diverse animal taxa. the production of exaggerated traits can come at a cost to other traits through trade-offs when resources allocated to trait development are limited. alternatively some traits can be selected for in parallel to support or compensate for the cost of bearing the exaggerated trait. male giraffe weevils (lasiorhynchus barbicornis) display an extremely elongated rostrum used as a weapon during contests for mate ...201324312425
testing the embodied account of object naming: a concurrent motor task affects naming artifacts and animals.embodied theories of object representation propose that the same neural networks are involved in encoding and retrieving object knowledge. in the present study, we investigated whether motor programs play a causal role in the retrieval of object names. participants performed an object-naming task while squeezing a sponge with either their right or left hand. the objects were artifacts (e.g. hammer) or animals (e.g. giraffe) and were presented in an orientation that favored a grasp or not. we hyp ...201424291119
the effect of intervertebral cartilage on neutral posture and range of motion in the necks of sauropod dinosaurs.the necks of sauropod dinosaurs were a key factor in their evolution. the habitual posture and range of motion of these necks has been controversial, and computer-aided studies have argued for an obligatory sub-horizontal pose. however, such studies are compromised by their failure to take into account the important role of intervertebral cartilage. this cartilage takes very different forms in different animals. mammals and crocodilians have intervertebral discs, while birds have synovial joints ...201324205163
regional differences in seasonal timing of rainfall discriminate between genetically distinct east african giraffe taxa.masai (giraffa tippelskirchi), reticulated (g. reticulata) and rothschild's (g. camelopardalis) giraffe lineages in east africa are morphologically and genetically distinct, yet in kenya their ranges abut. this raises the question of how divergence is maintained among populations of a large mammal capable of long-distance travel, and which readily hybridize in zoos. here we test four hypotheses concerning the maintenance of the phylogeographic boundaries among the three taxa: 1) isolation-by-dis ...201324194870
protection against high intravascular pressure in giraffe legs.the high blood pressure in giraffe leg arteries renders giraffes vulnerable to edema. we investigated in 11 giraffes whether large and small arteries in the legs and the tight fascia protect leg capillaries. ultrasound imaging of foreleg arteries in anesthetized giraffes and ex vivo examination revealed abrupt thickening of the arterial wall and a reduction of its internal diameter just below the elbow. at and distal to this narrowing, the artery constricted spontaneously and in response to nore ...201324005251
all giraffes have female-specific properties: influence of grammatical gender on deductive reasoning about sex-specific properties in german speakers.grammatical gender is independent of biological sex for the majority of animal names (e.g., any giraffe, be it male or female, is grammatically treated as feminine). however, there is apparent semantic motivation for grammatical gender classes, especially in mapping human terms to gender. this research investigated whether this motivation affects deductive inference in native german speakers. we compared german with japanese speakers (a language without grammatical gender) when making inferences ...201423957504
a selective deficit in imageable concepts: a window to the organization of the conceptual system.nissim, a 64 years old hebrew-speaking man who sustained an ischemic infarct in the left occipital lobe, exhibited an intriguing pattern. he could hold a deep and fluent conversation about abstract and complex issues, such as the social risks in unemployment, but failed to retrieve imageable words such as ball, spoon, carrot, or giraffe. a detailed study of the words he could and could not retrieve, in tasks of picture naming, tactile naming, and naming to definition, indicated that whereas he w ...201323785321
why sauropods had long necks; and why giraffes have short necks.the necks of the sauropod dinosaurs reached 15 m in length: six times longer than that of the world record giraffe and five times longer than those of all other terrestrial animals. several anatomical features enabled this extreme elongation, including: absolutely large body size and quadrupedal stance providing a stable platform for a long neck; a small, light head that did not orally process food; cervical vertebrae that were both numerous and individually elongate; an efficient air-sac-based ...201323638372
sensorimotor responsiveness and resolution in the giraffe.the ability of an animal to detect and respond to changes in the environment is crucial to its survival. however, two elements of sensorimotor control - the time required to respond to a stimulus (responsiveness) and the precision of stimulus detection and response production (resolution) - are inherently limited by a competition for space in peripheral nerves and muscles. these limitations only become more acute as animal size increases. in this paper, we investigated whether the physiology of ...201323447665
multi-scale clustering by building a robust and self correcting ultrametric topology on data points.the advent of high-throughput technologies and the concurrent advances in information sciences have led to an explosion in size and complexity of the data sets collected in biological sciences. the biggest challenge today is to assimilate this wealth of information into a conceptual framework that will help us decipher biological functions. a large and complex collection of data, usually called a data cloud, naturally embeds multi-scale characteristics and features, generically termed geometry. ...201323424653
left ventricular morphology of the giraffe heart examined by stereological methods.the giraffe heart has a relative mass similar to other mammals, but generates twice the blood pressure to overcome the gravitational challenge of perfusing the cerebral circulation. to provide insight as to how the giraffe left ventricle (lv) is structurally adapted to tackle such a high afterload, we performed a quantitative structural study of the lv myocardium in young and adult giraffe hearts. tissue samples were collected from young and adult giraffe lv. design-based stereology was used to ...201323420662
early primate evolution in afro-arabia.the peculiar mammalian fauna that inhabited afro-arabia during the paleogene first came to the attention of the scientific community in the early part of the twentieth century, when andrews1 and schlosser2 published their landmark descriptions of fossil mammals from the fayum depression in northern egypt. their studies revealed a highly endemic assemblage of land mammals that included the first known paleogene records of hyraxes, proboscideans, and anthropoid primates, but which lacked ancestors ...201223280921
nonprobative photographs (or words) inflate truthiness.when people evaluate claims, they often rely on what comedian stephen colbert calls "truthiness," or subjective feelings of truth. in four experiments, we examined the impact of nonprobative information on truthiness. in experiments 1a and 1b, people saw familiar and unfamiliar celebrity names and, for each, quickly responded "true" or "false" to the (between-subjects) claim "this famous person is alive" or "this famous person is dead." within subjects, some of the names appeared with a photo of ...201222869334
neonatal incubators: a toxic sound environment for the preterm infant?*.high sound pressure levels may be harmful to the maturing newborn. current guidelines suggest that the sound pressure levels within a neonatal intensive care unit should not exceed 45 db(a). it is likely that environmental noise as well as the noise generated by the incubator fan and respiratory equipment may contribute to the total sound pressure levels. knowledge of the contribution of each component and source is important to develop effective strategies to reduce noise within the incubator.201222791088
hypertensive cardiovascular and renal disease and target organ damage: lessons from animal models.this brief review discusses some aspects of hypertensive damage to the kidneys and cardiovascular system. a comparison of renal and cardiac manifestations of hypertensive disease between results of clinical and experimental studies was made, with a major focus on the possible role of salt and the renin-angiotensin system (ras) in inducing target organ damage. thus, some degree of renal impairment is often present in patients with essential hypertension, varying from microalbuminuria to end-stage ...201122258536
understanding selection for long necks in different taxa.there has been recent discussion about the evolutionary pressures underlying the long necks of extant giraffes and extinct sauropod dinosaurs. here we summarise these debates and place them in a wider taxonomic context. we consider the evolution of long necks across a wide range of (both living and extinct) taxa and ask whether there has been a common selective factor or whether each case has a separate explanation. we conclude that in most cases long necks can be explained in terms of foraging ...201222171805
misconceived causal explanations for emergent processes.studies exploring how students learn and understand science processes such as diffusion and natural selection typically find that students provide misconceived explanations of how the patterns of such processes arise (such as why giraffes' necks get longer over generations, or how ink dropped into water appears to "flow"). instead of explaining the patterns of these processes as emerging from the collective interactions of all the agents (e.g., both the water and the ink molecules), students oft ...201222050726
how long to air sample? practical considerations for short-term air sampling.transportable (e.g., "giraffe") air samplers can be used for both short-term "grab-sampling" situations involving a few minutes to several hours, as well as for long-term retrospective air sampling situations that typically last a week. it is the short-term coverage situation which begs the question: "how long a sampling time is adequate?" the basis for the answer (which depends mainly on the selected volumetric sampling rate and the counter sensitivity, as well as the concentration level to be ...201121709490
spinal cord injury during recovery from anaesthesia in a giraffe. 201121672949
sonographic patterns of benign thyroid nodules: verification at our institution.the objective of our study was to apply the sonographic criteria for the diagnosis of benign thyroid nodules described by bonavita et al. to our patient referral population.201121427342
pressure profile and morphology of the arteries along the giraffe limb.giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists for centuries. the authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright standing position, and determined the ratio between tunica media and lumen areas along the length of the femoral/tibial arteries in the hindleg. volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. imm ...201121207038
intraocular metastasis of testicular natural killer t-cell lymphoma with diffuse retinal pigment epithelium changes.the purpose of this study was to report the first confirmed case of testicular natural killer t-cell lymphoma with bilateral intraocular metastasis.201125389681
the sound of operation and the acoustic attenuation of the ohmeda medical giraffe omnibed™.the neonatal intensive care unit (nicu) is an environment that provides premature and fragile infants with health provisions needed to make a complete recovery. premature infants are often born before their auditory systems have had an opportunity to fully mature. research has shown that the ambient acoustic environment in the nicu exceeds the maximum noise level recommended by the american academy of pediatrics, even after measures have been taken to decrease noise levels. the purpose of this s ...201021173485
cognitive flexibility in drawings of bilingual children.a. karmiloff-smith's (1990) task of drawing a nonexistent object is considered to be a measure of cognitive flexibility. the notion of earlier emergence of cognitive flexibility in bilingual children motivated the current researchers to request 4- and 5-year-old english-hebrew and arabic-hebrew bilingual children and their monolingual peers to draw a flower and a house that do not exist (n=80). bilinguals exhibited a significantly higher rate of interrepresentational flexibility in their drawing ...201020840226
consistency of captive giraffe behavior under two different management regimes.long-term animal behavior studies are sometimes conducted at a single site, leading to questions about whether effects are limited to animals in the same environment. our ability to make general conclusions about behavior is improved when we can identify behaviors that are consistent across a range of environments. to extend veasey and colleagues' ([1996b] anim welf 5:139-153) study, i compared not only activity budgets but also social behavior of an all-female group of giraffe at the maryland z ...201120717898
how name descriptiveness impacts proper name learning in young and older adults.to elucidate the impact of name descriptiveness and aging on learning new names, 26 young and 26 healthy older participants learned visibly-descriptive (e.g., lengthy for a giraffe), psychologically-descriptive (e.g., classy), and non-descriptive (e.g., sam) proper names for previously-unknown cartoon characters. more visibly-descriptive names were learned than psychologically- or non-descriptive names, which did not differ from each other. there was also a differential benefit for older adults ...201020349368
improved care and growth outcomes by using hybrid humidified incubators in very preterm infants.to identify changes in temperature, fluid and electrolyte management, growth, and short-term outcome in extremely low birth weight (elbw) infants nursed in humidified hybrid incubators (hi group) compared with a cohort of patients cared for in nonhumidified conventional incubators (ci group).201020026493
multi-channel real time active noise control system for infant incubators.excessive noise levels inside infants incubators in neonatal intensive care units (nicu) contribute to number of harmful effects on the infant's health. this paper develops and implements practical active noise control (anc) systems for the infant incubators. the filtered-x least mean square (fxlms) algorithm is used to cancel the noise inside the incubator. the multi-channel and pseudo multi-channel anc systems are proposed to enhance the noise cancellation performance in terms of cancellation ...200919964251
a purple giraffe is faster than a purple elephant: inconsistent phonology affects determiner selection in english.the form of a determiner is dependent on different contextual factors: in some languages grammatical number and grammatical gender determine the choice of a determiner variant. in other languages, the phonological onset of the element immediately following the determiner affects selection, too. previous work has shown that the activation of opposing determiner forms by a noun's grammatical properties leads to slower naming latencies in a picture naming task, as does the activation of opposing fo ...201019853845
analysis of nutrient concentrations in the diet, serum, and urine of giraffe from surveyed north american zoological institutions.the objectives of the present research were to conduct a survey to investigate the health history and feeding practices of giraffe in captivity in north america and to obtain samples of hay, concentrate, browse, urine, and serum to compare across zoos, possible factors relating to the development of urolithiasis. forty-one out of 98 institutions contacted responded, representing 218 giraffe. all responding zoos fed concentrate and alfalfa hay was the primary forage. sixty-five percent of zoos fe ...201019816905
organization of cholinergic, putative catecholaminergic and serotonergic nuclei in the diencephalon, midbrain and pons of sub-adult male giraffes.the current study describes the nuclear organization and neuronal morphology of the cholinergic, putative catecholaminergic and serotonergic systems within the diencephalon, midbrain and pons of the giraffe using immunohistochemistry for choline acetyltransferase, tyrosine hydroxylase and serotonin. the giraffe has a unique phenotype (the long neck), a large brain (over 500 g) and is a non-domesticated animal, while previous studies examining the brains of other artiodactyls have all been undert ...201019808092
an allometric analysis of the giraffe cardiovascular system.there has been co-evolution of a long neck and high blood pressure in giraffes. how the cardiovascular system (cvs) has adapted to produce a high blood pressure, and how it compares with other similar sized mammals largely is unknown. we have measured body mass and heart structure in 56 giraffes of both genders ranging in body mass from 18 kg to 1500 kg, and developed allometric equations that relate changes in heart dimensions to growth and to cardiovascular function. predictions made from thes ...200919720152
jugular venous pooling during lowering of the head affects blood pressure of the anesthetized giraffe.how blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. we measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. the giraffes were suspended in the upright position so that we could lower the head. in the upright position, mean arterial pressure (map) was 193 +/- 11 mmhg (mean +/- se), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectio ...200919657096
pattern recognition of benign nodules at ultrasound of the thyroid: which nodules can be left alone?the purpose of this study was to evaluate morphologic features predictive of benign thyroid nodules.200919542415
three extant genera of freshwater thalassiosiroid diatoms from middle eocene sediments in northern canada.the evolutionary history of diatoms is only constrained partially by the fossil record. the timing of several key events, such as initial colonization of freshwater habitats by marine taxa, remains poorly resolved. numerous specimens of the genera cyclotella, discostella, and puncticulata (ochrophyta: thalassiosirales) have been recovered in middle eocene lacustrine sediments from the giraffe pipe locality in the northwest territories, canada. these diatoms extend the fossil record of the family ...200921628204
fatal dystocia in a giraffe due to a pelvic chondrosarcoma. 200818344502
cerebral perfusion pressure in giraffe: modelling the effects of head-raising and -lowering.loss of consciousness caused by positional changes of the head results from reduced cerebral blood flow (cbf). cbf is related to cerebral perfusion pressure (cpp). cpp is the difference between mean arterial pressure (map) at the head and intracranial pressure (icp). the positional change of the giraffe head between ground level and standing upright is the largest of all animals yet loss of consciousness does not occur. we have investigated the possibility that an increase in cpp protects giraff ...200818329049
attachment and sibling rivalry in little hans: the fantasy of the two giraffes revisited.freud's interpretation of little hans's "phantasy of the two giraffes" is pivotal to his oedipal analysis that hans has inchoate desires for sexual intercourse with his mother. bowlby argued that freud's focus on his oedipal theory led him to ignore preoedipal attachment-related factors that have equal plausibility in explaining the clinical data. however, bowlby did not attempt to apply the attachment perspective to the interpretation of hans's fantasies that form the core of the case material. ...200717915649
winning by a neck: tall giraffes avoid competing with shorter browsers.with their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. they ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. we erected exclosures around individual acacia nigrescens trees in the ...200717206591
fecal progestagen and estrone during pregnancy in a giraffe: a case report.the present study was carried out to measure fecal progestagen and estrone concentrations during pregnancy in a giraffe and examine the possibility of utilizing this assay system for pregnancy diagnosis. fecal samples were collected from a giraffe during her third and fourth parities and mixed with methanol to prepare a fecal solution. diluted fecal solution was used for direct enzyme immunoassay for progestagen and estrone. the newborn calf from the third parity was viable, although that from t ...200717008760
optimizing the neonatal thermal environment.devices used to maintain thermal stability in preterm infants have advanced over time from the first incubator reported by jean-louis-paul denuce in 1857 to the latest versalet incuwarmer and giraffe omnibed devices today. optimizing the thermal environment has proven significant for improving the chances of survival for small infants. understanding the basic physiologic principles and current methodology of thermoregulation is important in the clinical care of these tiny infants. this article h ...200816913236
["giraffe omnibed--a bed for all? warm heat therapy device has multiple applications]. 200616883738
the origin of mean arterial and jugular venous blood pressures in giraffes.using a mechanical model of the giraffe neck and head circulation consisting of a rigid, ascending, 'carotid' limb, a 'cranial' circulation that could be rigid or collapsible, and a descending, 'jugular' limb that also could be rigid or collapsible, we have analyzed the origin of the high arterial and venous pressures in giraffe, and whether blood flow is assisted by a siphon. when the tubes were rigid and the 'jugular' limb exit was lower than the 'carotid' limb entrance a siphon operated, 'car ...200616788035
long-term suppression of fertility in female giraffe using the gnrh agonist deslorelin as a long-acting implant.zoological institutions provide an environment conducive to studying proximate mechanisms influencing reproduction that can provide guidance to both field and captive settings seeking to manage their stock. both national parks and zoos have space limitations that sometimes require the use of reversible contraception in order to reduce reproductive rate or limit specific individuals from reproducing. we designed a study to test the efficacy of a long-lasting contraceptive in female giraffe by mon ...200616423382
contact urticaria to giraffe hair.immediate-type hypersensitivity to animal proteins is a common problem in people occupationally exposed to animals.200516224192
naming a giraffe but not an animal: base-level but not superordinate naming in a patient with impaired semantics.we report data on patient fk, who presented with a marked deficit in accessing semantic knowledge about objects when tested across a range of input and output modalities. fk also showed a high degree of item-specific consistency in object identification, over and above effects due to object familiarity. we show that, despite being better at naming some objects than others, fk was equally poor at discriminating the superordinate categories of the stimuli. also, he tended to be better at matching ...200521038265
independent access to phonological and orthographic lexical representations: a replication study.traditionally, it has been assumed that written abilities are completely dependent on phonology (the so-called phonological mediation theory). in this view, the semantic system activates the phonological form of a word, which then activates the corresponding orthographic representation. this hypothesis predicts that in double naming tasks (two temporally close responses to the same picture in the two output modalities), the word selected for a written response will always correspond to the one s ...200415788267
[lung cancer screening revisited -- are we merely combing a giraffe?]. 200515756628
musical structure modulates semantic priming in vocal music.it has been shown that harmonic structure may influence the processing of phonemes whatever the extent of participants' musical expertise [bigand, e., tillmann, b., poulin, b., d'adamo, d. a., & madurell, f. (2001). the effect of harmonic context on phoneme monitoring in vocal music. cognition, 81, b11-b20]. the present study goes a step further by investigating how musical harmony may potentially interfere with the processing of words in vocal music. eight-chord sung sentences were presented, t ...200515617668
effects of body size on the diurnal activity budgets of african browsing ruminants.we compared the diurnal activity budgets of four syntopic species of african browsing ruminant that differ widely in body size. these were concurrently studied through all phases of the seasonal cycle, in the same area, using the same methods. we tested five predictions from the literature on how body size is expected to influence the behaviour of tropical ungulates: the smallest members of the browsing ruminant guild exhibit (1) the lowest allocation of diurnal time to activity; (2) the greates ...200515605272
a triassic aquatic protorosaur with an extremely long neck.by middle triassic time, a number of reptile lineages had diversified in shallow epicontinental seas and intraplatform basins along the margins of parts of pangea, including the giraffe-necked protorosaurid reptile tanystropheus from the western tethys (europe and the middle east), which grew to approximately 5 to 6 m long. here we report another long-necked fossil, dinocephalosaurus, from southwestern china, recently collected in middle triassic marine deposits approximately 230 million years o ...200415448262
the giraffe: the emergency care practitioner; fit for purpose? the east anglian experience. 200415107385
insights from stable light isotopes on enamel defects and weaning in pliocene herbivores.a high prevalence of enamel hypoplasia in several herbivores from the early pliocene langebaanweg locality, south africa, indicates general systemic stress during the growing years of life. the presence of several linear enamel hypoplasias per tooth crown in many teeth further suggest that these stress events may be episodic. the delta18o values along tooth crowns of mandibular second molars of sivatherium hendeyi (artiodactyla, giraffidae) were used to investigate the cause of the stress events ...200314660876
problem-solving by traumatically brain injured and neurologically intact subjects on an adaptation of the twenty questions test.raps (rapid assessment of problem-solving) is a clinical measure for assessing verbal problem-solving in hard-to-test patients or those that may not be able to tolerate a longer, more detailed assessment. the design of the test is based on mosher and hornsby's twenty question test, but raps contains several modifications to facilitate its use with brain-injured individuals. this study used raps to compare the verbal problem-solving ability of subjects that were neurologically intact and subjects ...200312775271
extreme morphological and ecological homoplasy in tropical salamanders.fossorial salamanders typically have elongate and attenuated heads and bodies, diminutive limbs, hands and feet, and extremely elongate tails. batrachoseps from california, lineatriton from eastern méxico, and oedipina from southern méxico to ecuador, all members of the family plethodontidae, tribe bolitoglossini, resemble one another in external morphology, which has evolved independently. whereas oedipina and batrachoseps are elongate because there are more trunk vertebrae, a widespread homopl ...200111427707
a survey assessment of variables related to stereotypy in captive giraffe and okapi.stereotypic behavior has been investigated in a wide variety of animals, but little published information is available on this problem in captive exotic ungulates. a survey was used to gather information on the prevalence of stereotypic behavior in giraffe and okapi and to identify variables associated with these behaviors. of the 71 institutions that received a survey, 69.0% responded. data were reported for 257 individuals, including 214 giraffe (representing five subspecies) and 29 okapi. of ...200111376840
diagnosis and treatment of a fractured third phalanx in a masai giraffe (giraffe camelopardalis tippelskirchi).a 10-yr-old male masai giraffe (giraffe camelopardalis tippelskirchi) presented with acute right forelimb lameness. radiographs revealed a fracture of the medial claw of the distal phalanx penetrating into the distal interphalangeal joint. the giraffe was sedated while it was standing in a chute, and a wooden "hoof block" was applied to the lateral claw of the same limb. the animal was no longer lame 3 days after the procedure. subsequent treatments included vitamin e, phenylbutazone, and glycos ...200011237150
use of medetomidine and ketamine for immobilization of free-ranging giraffes.to develop a dosage correlated with shoulder height (sh) in centimeters for effective immobilization of free-ranging giraffes, using a combination of medetomidine (med) and ketamine (ket) and reversal with atipamezole (atp).200111195833
the light chain binding domain of expressed smooth muscle heavy meromyosin acts as a mechanical lever.structural data led to the proposal that the molecular motor myosin moves actin by a swinging of the light chain binding domain, or "neck." to test the hypothesis that the neck functions as a mechanical lever, smooth muscle heavy meromyosin (hmm) mutants were expressed with shorter or longer necks by either deleting or adding light chain binding sites. the mutant hmms were characterized kinetically and mechanically, with emphasis on measurements of unitary displacements and forces in the laser t ...200010945998
testing the interspecific body size principle in ungulates: the smaller they come, the harder they groom.tick removal grooming may be centrally regulated by an internal timing mechanism operating to remove ticks before they attach and engorge (programmed grooming model) and/or evoked by cutaneous stimulation from tick bites (stimulus-driven model). the programmed grooming model predicts that organismic and environmental factors that impact the cost-benefit ratio of grooming (e.g. body size and habitat) will influence the rate of tick removal grooming. the body size principle predicts that smaller-s ...200010924201
giraffes, siphons, and starling resistors. cerebral perfusion pressure revisited. 200010905578
model analogues in the study of cephalic circulation.simple laboratory models are useful to demonstrate cardiovascular principles involving the effects of gravity on the distribution of blood flow to the heads of animals, especially tall ones like the giraffe. they show that negative pressures cannot occur in collapsible vessels of the head, unless they are protected from collapse by external structures such as the cranium and cervical vertebrae. negative pressures in the cerebral-spinal fluid (csf) can prevent cerebral circulation from collapsing ...200010840228
mucus liquid crystallinity: is function related to microstructural domain size?the size of liquid crystalline domains formed in partially dried giraffe saliva is found to be an order of magnitude greater than that previously documented for slug pedal mucus. a correlation between (a) intrinsic liquid crystalline domain size and (b) the scale of surface topography over which the mucus is required to provide lubrication is postulated. the scale of mucus microstructure can be related, via a simple model, to two significant material constants: the elastic constant k for distort ...199910690268
the contribution of the giraffe to hemodynamic knowledge: a unified physical principle for the circulation.hemodynamics stands on three main physical principles: the hydrostatic pressure, firstly described by stevino, the viscous flow pressure, described by poiseuille and the total hydraulic energy, or bernoulli's equation. however, neither of these physical principles gives a comprehensive description of the single pressure measurement in the cardiovascular system. hence, all these principles should be used together to fully describe the physical forces acting in the circulation of blood. experiment ...199910609386
cardiac output measurement in an anaesthetised giraffe. 199910596874
do giraffe roar? 199910452401
symmetry breaking and adaptation: evidence from a 'toy model' of a virus.we argue that an induced breaking of the genetic synonym symmetry due to the action of genetic operators such as mutation can enhance the adaptability of a species to changes in the environment. in the case of a virus, the claim is that the codon bias in the neutralization epitope improves the virus' ability to generate mutants that evade the induced immune response. we support our claim with a simple 'toy model' of a viral epitope evolving in competition with the immune system. the effective se ...199910426468
is the flow in the giraffe's jugular vein a "free" fall?there is controversy as to whether or not the heart works against gravity in the arteries to the head in the upright position. one view is that the gravitational effects in the neck arteries are counterbalanced by the gravitational effects in the veins of the neck and the heart does not do extra pressure work. this concept has been challenged by others who claim that the heart works against gravity based on the notion that the jugular vein is collapsed and gravitational effects on jugular blood ...19979406435
blood pressure and flow rate in the giraffe jugular vein.experimental measurements in the jugular veins of upright giraffes have shown that the internal pressure is somewhat above atmospheric and increases with height above the heart. a simple model of steady viscous flow in an inverted u-tube shows that these observations are inconsistent with a model in which the blood vessels in the head and neck are effectively rigid and the system resembles a siphon. instead, the observations indicate that the veins are collapsed and have a high resistance to flo ...19968856806
[communication model. wolf or giraffe--that is the question]. 19968716059
large african herbivores, bruchid beetles and their interactions with acacia seeds.this study investigated the interactions of large african herbivores and bruchid seed beetles with acacia seeds. the germination of bruchid-infested and uninfested seeds was compaed. the effects of pod consumption by large herbivores on bruchid infestation and seed germination was also assessed. bruchid-infested seeds did germinate, and the germination of bruchid-infested and uninfested a. tortilis, a. nilotica and a. hebeclade seeds did not differ. pod ingestion by large herbivores lowered the ...199428313938
["giraffe language" for understanding of feelings/needs]. 19938231482
["giraffe language"--new "high-class" medical terminology?]. 19938361265
on giraffes and peer review. 19938500686
symbiotic ants as an alternative defense against giraffe herbivory in spinescent acacia drepanolobium.we explore here the occurrence of aggressive ants in an apparently symbiotic relationship with the savanna tree acacia drepanolobium and their effects on giraffe herbivory on the athi-kapiti plains, kenya. trees taller than 1.3 m were more likely to be occupied by aggressive ants in the genus crematogaster than were shorter trees. ants wereconcentrated on shoot tips, the plant parts preferred by giraffes. trees with relatively more foliage had more swarming ants than did trees with less foliage. ...199228313462
hemodynamics of vascular 'waterfall': is the analogy justified?the concept of 'vascular waterfall' has been used for collapsible vessels in different hemodynamic states which have little similarity to each other from a dynamic standpoint. examples include (a) flow through large systemic veins entering the thorax, (b) flow through microvessels, such as pulmonary, cardiac, hepatic, cerebral, and (c) flow through the jugular vein of the giraffe. the dynamics of freely falling liquids (waterfall) as compared with flow through collapsible blood vessels (in vivo ...19921565893
"giraffe fetus". 19911917827
development of the giraffe horn and its blood supply.the giraffe horn is an unusual cranial exostosis that lacks clear delineation and categorization as either horn or antler. the distinction between the two is made by contrasting their methods of development and basic composition. this process of development has not been detailed in the giraffe, a factor contributing to the difficulty in distinguishing the classification of these horns. in a chronological series of giraffe horns from prenatal and postnatal animals, we have observed unique morphol ...19902393101
[the sistrunk median cervical cyst operation using a cecal foramen pointer].the cecal foramen pointer was invented for a sistrunk median cervical cyst operation. the instrument consists of three elements, namely: the cecal foramen holder, the giraffe shaped connector and the pointer needle. first of all, the cecal foramen is held by the holder which is reconstructed from hemostatic forceps. the one end of the connector is joined to the holder's handle. then the other end of the connector comes along the patient's chin, in front of the neck. the cyst and mid-portion of t ...19902398862
siphon mechanism in collapsible tubes: application to circulation of the giraffe head.controversy exists over the principles involved in determining blood flow to the head of a giraffe, specifically over the role of gravity pressure (pgh) in the collapsible jugular vein in facilitating uphill flow in arteries. this study investigated the pressures within vertically oriented models containing both rigid and collapsible tubes. an inverted u tube was constructed (height = 103 cm) of thick rubber tubing in the ascending limb and collapsible dialysis tubing in the descending limb. wat ...19892916707
[the immobilization of giraffes].the anatomical and physiological conditions of blood circulation in the giraffe are pointed out. 16 immobilizations in the giraffe of either sex are reported, of which 10 were immobilized according to the following scheme. 1. premedication: 30 mg xylazine 150 mg hyaluronidase 2. 15 minutes later a halter with two long ropes is put on to hold up the animals' heads after they lay down. 3. 20 minutes after premedication the injection of 5.6-6.0 mg etorphine (2.5-2.7 ml immobilon) together with 150 ...19892718168
[fetlock joint flexion as the cause of a labor complication in a giraffe]. 19883053098
haemodynamics of the jugular vein in the giraffe. 19883357547
sympathetic innervation of the cardiovascular system in the giraffe.the extreme blood pressure gradients in the giraffe, produced by gravity and behaviour, present a special challenge to blood flow and vascular capacity regulation, e.g. via sympathetic nerves. we report the distribution of nerves in vascular tissue from giraffe extremities and neck based on immunofluorescence against specific antisera to dopamine-beta-hydroxylase, neuropeptide y, neurofilament, and synapsin i. sympathetic innervation of gravitation-dependent arteries in the limbs was restricted ...19883203141
vascular system of the giraffe. 20033657985
haemodynamics: how giraffes prevent oedema. 20073627232
gravitational cardiovascular adaptation in the giraffe. 19873562614
blood flow uphill and downhill: does a siphon facilitate circulation above the heart?1. despite the continuity of the circulatory system, blood flowing down the veins of the neck does not assist blood flowing up the arteries. because of collapsible veins, gravitational pressure gradients are not matched in arterial and venous sides of circulatory loops above the heart as would be necessary for a siphon to operate. 2. all animals have arterial blood pressures capable of lifting the blood to the head without the assistance from a siphon. in cases of longer vertical distances, such ...19872890463
does gravitational pressure of blood hinder flow to the brain of the giraffe?vascular pressure consists of the sum of two pressures: (a) pressure developed by the pumping of the ventricles against the resistance of vessels, designated as viscous flow pressure, and (b) pressure caused by gravity, traditionally called hydrostatic, better described as gravitational pressure. in a conduit, both of these pressures must be overcome when a liquid is discharged to a higher level of gravitational potential energy. if a liquid is returned to its original level, gravity neither hel ...19862869860
listeriosis in angolan giraffes. 19854077652
dystocia and fatal hyperthermic episode in a giraffe. 19846511615
giant verrucous carcinoma in a giraffe.an 18-year-old male giraffe developed a verrucous lesion, 50 cm in diameter, on a flank. some areas of the lesion were histologically typical of a viral verruca with papillomatosis, prominent hypergranulosis, and inclusion bodies. the bulk of the mass was a well-differentiated verrucous type of squamous cell carcinoma. it may be that the virus of the verruca also caused the verrucous carcinoma.19846703261
some uterine parameters in antelopes and a giraffe.uteri of 69 african antelopes and a giraffe were morphologically examined and numbers of caruncles and their rows in each horn were recorded. antelopes of subfamilies taurotraginae, aepycerotinae, antilopinae, and alcelaphinae had about 50 to 100 caruncles arranged in four rows in each uterine horn. hippotraginae had about 100 to 200 caruncles in six to eight rows in each horn, and reduncinae had about 10 to 20 caruncles in two rows in each uterine horn. the giraffe had about 70 caruncles arrang ...198316725864
the bronchial ramification and lobular division of the giraffe lung.the right lung of the giraffe consists of bilobed upper, middle, accessory and lower lobes. the middle and lower lobes are united to form one lobe. the left lung consists of bilobed upper, middle and lower lobes. the middle and lower lobes are adhered.19836660545
respiration and metabolism in the giraffe.measurements have been made on respiration of three resting unstressed adult giraffe under normal conditions. tracheal dimensions and body dimensions have also been measured in a large number of giraffe and other mammals. the results indicate that contrary to statements in the literature the giraffe does not have an abnormally large dead space, though the trachea is abnormally long and narrow. the respiratory measurements indicate that the giraffe breathes as predicted by published scaling equat ...19827156526
on pattern formation mechanisms for lepidopteran wing patterns and mammalian coat markings.the patterns on wings of lepidoptera can be generated with a few pattern elements, but no mechanism has been suggested for producing them. i consider two of the basic patterns, namely, central symmetry and dependent patterns. a biochemically plausible model mechanism is proposed for generating major aspects of these patterns, based on a diffusing morphogen that activates a gene or colour-specific enzyme in a threshold manner to generate a stable heterogeneous spatial pattern. the model is applie ...19816117906
["giraffe women" of the high plateaus of burma]. 19806448562
[delivery and breeding problems in the cape giraffes of the cologne zoo]. 1978644581
[electron miscroscopy studies of the chorion epithelium of giraffe placenta]. 1977611746
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