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structure and innervation of the tusk pulp in the african elephant (loxodonta africana).african elephants (loxodonta africana) use their tusks for digging, carrying and behavioural display. their healing ability following traumatic injury is enormous. pain experience caused by dentin or pulp damage of tusks seems to be negligible in elephants. in this study we examined the pulp tissue and the nerve distribution using histology, electron microscopy and immunhistochemistry. the results demonstrate that the pulp comprises two differently structured regions. randomly orientated collage ...200515817106
animal behaviour: elephants are capable of vocal learning.there are a few mammalian species that can modify their vocalizations in response to auditory experience--for example, some marine mammals use vocal imitation for reproductive advertisement, as birds sometimes do. here we describe two examples of vocal imitation by african savannah elephants, loxodonta africana, a terrestrial mammal that lives in a complex fission-fusion society. our findings favour a role for vocal imitation that has already been proposed for primates, birds, bats and marine ma ...200515791244
the sexually active states of free-ranging male african elephants (loxodonta africana): defining musth and non-musth using endocrinology, physical signals, and behavior.musth in male african elephants, loxodonta africana, is associated with increased aggressive behavior, continuous discharge of urine, copious secretions from the swollen temporal glands, and elevated androgen levels. during musth, bulls actively seek out and are preferred by estrous females although sexual activity is not restricted to the musth condition. the present study combines recently established methods of fecal hormone analysis with long-term observations on male-female associations as ...200515579269
assigning african elephant dna to geographic region of origin: applications to the ivory trade.resurgence of illicit trade in african elephant ivory is placing the elephant at renewed risk. regulation of this trade could be vastly improved by the ability to verify the geographic origin of tusks. we address this need by developing a combined genetic and statistical method to determine the origin of poached ivory. our statistical approach exploits a smoothing method to estimate geographic-specific allele frequencies over the entire african elephants' range for 16 microsatellite loci, using ...200415459317
the return of the giants: ecological effects of an increasing elephant population.northern botswana and adjacent areas, have the world's largest population of african elephant (loxodonta africana). however, a 100 years ago elephants were rare following excessive hunting. simultaneously, ungulate populations were severely reduced by decease. the ecological effects of the reduction in large herbivores must have been substantial, but are little known. today, however, ecosystem changes following the increase in elephant numbers cause considerable concern in botswana. this was the ...200415387059
musculature of the crus and pes of the african elephant (loxodonta africana): insight into semiplantigrade limb architecture.the limbs of elephants are designed to support the weight of the largest terrestrial animal, and they display unique morphological peculiarities among mammals. in this article we provide a new and detailed anatomical description of the muscles of the lower hindlimb in african elephants (loxodonta africana), and we place our observations into a comparative anatomical as well as a functional morphological context. at the cranial aspect of the shank (crus) and the foot (pes), the flexors of the tar ...200415340844
neural innervation of the tusk pulp of the african elephant (loxodonta africana). 200415074329
fetomaternal glycosylation of early placentation events in the african elephant loxodonta africana.during implantation in the african elephant (loxodonta africana), fetal trophoblast displaces the surface uterine epithelium and superficially penetrates the uterine glands. this limited invasion is followed by the upgrowth of blunt fingers of endometrial stroma, covered with trophoblast and containing capillaries that subsequently vascularize the growing placenta. we have used lectin histochemistry to compare the glycosylation of maternal endothelial cells in the endometrium with those growing ...200415028423
non-invasive assessment of adrenocortical function in the male african elephant (loxodonta africana) and its relation to musth.adult male elephants periodically show the phenomenon of musth, a condition associated with increased aggressiveness, restlessness, significant weight reduction and markedly elevated androgen levels. it has been suggested that musth-related behaviours are costly and that therefore musth may represent a form of physiological stress. in order to provide data on this largely unanswered question, the first aim of this study was to evaluate different assays for non-invasive assessment of adrenocortic ...200314511986
placentation in the african elephant (loxodonta africana): ii morphological changes in the uterus and placenta throughout gestation.the gross and microscopic development of the zonary endotheliochorial placenta in the african elephant was studied in 22 gravid uteri that ranged in gestational stage from 0.5 to 20.6 months. the conceptus only ever occupies one horn of the uterus and is associated with 2-5 large corpora lutea that persist in the ipsilateral ovary throughout gestation. initially, the trophoblast in the equatorial region of the conceptus completely replaces the lumenal epithelium of the endometrium to which it is ...200312828919
the use of low-frequency vocalizations in african elephant(loxodonta africana) reproductive strategies.fertility-advertisement calls in females are predicted to occur in nonmonogamous species where males and females are widely separated in space. in african elephants, low-frequency vocalizations have thus been suggested as a reproductive strategy used by fertile females to attract mates. this study examined the use of low-frequency vocalizations with respect to different phases of the estrous cycle in african elephants by simultaneously monitoring vocalizations, behavior, and hormonal profiles. s ...200312788289
a simple method of providing intermittent positive-pressure ventilation to etorphine-immobilized elephants (loxodonta africana) in the field.five african elephants (loxodonta africana) were immobilized with etorphine in waza national park, cameroon, for the purpose of deploying radio/satellite tracking collars. a portable ventilator constructed from two high-flow demand valves and the y-piece of a large animal anesthesia circuit was used to provide intermittent positive-pressure ventilation with 100% oxygen. oxygenation status improved dramatically in all five elephants. in one hypoxemic elephant, arterial pao2 increased from 40 to 3 ...200112785710
induced elephant (loxodonta africana) tusk removal.elephant tusk removal usually requires costly surgical procedures that are time-consuming and present a significant risk to the animal when performed using general anesthesia. such techniques require gauges, chisels, and forceps to remove the tusk. this article reports the simple removal of the tusk of an 18-yr-old african elephant (loxodonta africana) without the use of surgical instruments and anesthesia. rubber elastics were placed around a tusk, causing loss of alveolar bone with subsequent ...200312723807
patterns of molecular genetic variation among african elephant populations.the highly threatened african elephants have recently been subdivided into two species, loxodonta africana (savannah or bush elephant) and l. cyclotis (forest elephant) based on morphological and molecular studies. a molecular genetic assessment of 16 microsatellite loci across 20 populations (189 individuals) affirms species level genetic differentiation and provides robust genotypic assessment of species affiliation. savannah elephant populations show modest levels of phylogeographic subdivisi ...200212453234
the evolution and phylogeography of the african elephant inferred from mitochondrial dna sequence and nuclear microsatellite markers.recent genetic results support the recognition of two african elephant species: loxodonta africana, the savannah elephant, and loxodonta cyclotis, the forest elephant. the study, however, did not include the populations of west africa, where the taxonomic affinities of elephants have been much debated. we examined mitochondrial cytochrome b control region sequences and four microsatellite loci to investigate the genetic differences between the forest and savannah elephants of west and central af ...200212396498
placentation in the african elephant, loxodonta africana. i. endocrinological aspects.placental and fetal tissues were recovered from the uteri of 59 pregnant elephant that ranged in estimated age from day 18 to month 21 of gestation. incubation of placenta and fetal gonad, alone or in combination, with tritium-labelled cholesterol, pregnenolone and androstenedione failed to yield any labelled progestagens or oestrogens from placenta, but did produce small amounts of labelled progesterone and 5alpha-dihydroprogesterone from fetal gonad. immunochemical staining of tissues with fou ...200212220150
population structure of the african savannah elephant inferred from mitochondrial control region sequences and nuclear microsatellite loci.two hundred and thirty-six mitochondrial dna nucleotide sequences were used in combination with polymorphism at four nuclear microsatellite loci to assess the amount and distribution of genetic variation within and between african savannah elephants. they were sampled from 11 localities in eastern, western and southern africa. in the total sample, 43 haplotypes were identified and an overall nucleotide diversity of 2.0% was observed. high levels of polymorphism were also observed at the microsat ...200212136410
chemosignalling of musth by individual wild african elephants (loxodonta africana): implications for conservation and management.elephants have extraordinary olfactory receptive equipment, yet this sensory system has been only minimally investigated in wild elephants. we present an in-depth study of urinary chemical signals emitted by individual, behaviourally characterized, wild male african elephants, investigating whether these compounds were the same, accentuated, or diminished in comparison with captive individuals. remarkably, most emitted chemicals were similar in captive and wild elephants with an exception traced ...200211958718
genetic evidence for two species of elephant in africa.elephants from the tropical forests of africa are morphologically distinct from savannah or bush elephants. dart-biopsy samples from 195 free-ranging african elephants in 21 populations were examined for dna sequence variation in four nuclear genes (1732 base pairs). phylogenetic distinctions between african forest elephant and savannah elephant populations corresponded to 58% of the difference in the same genes between elephant genera loxodonta (african) and elephas (asian). large genetic dista ...200111520983
the measurement of glucocorticoid concentrations in the serum and faeces of captive african elephants (loxodonta africana) after acth stimulation.conventionally, the assessment of adrenal responses to stress relies on blood sample collection. however, blood collection from animals is impossible without restraint or immobilisation that influences results. this study was undertaken to validate recently established enzyme immunoassays that measure faecal glucocorticoid metabolites in elephants, and to perform a preliminary investigation into the biological relevance of this non-invasive method for use in assessing the degree of stress in thi ...200011205170
radiographic diagnosis of lameness in african elephants (loxodonta africana).lameness in captive elephants is most commonly caused by pododermatitis or degenerative joint disease. hard surfaces such as concrete, which produce a damp and cold environment, wet and muddy conditions, as well as restricted movement are the major causes of these problems. radiography was performed in two african elephants at the schoenbrunn zoo in vienna to determine the cause and extent of lameness. various radiographic techniques are described for use in trained elephants. low time settings ...201611130790
early development of the tush and the tusk of the african elephant (loxodonta africana).this early development was studied from a serial histological sections of eight elephant embryos with masses varying between 1 and 240 g. the tush and the tusk develop from one tooth germ in a deciduous to permanent tooth relation. in order to study the mineralization of the dental organ of the tush and cap and bell stage of the tusk, embryos older than 3-months' gestation (weighing more than 250 g) would be required.200011000384
polymorphic microsatellite dna loci identified in the african elephant (loxodonta africana). 200010886668
serum oxytetracycline concentrations in african elephant (loxodonta africana) calves after long-acting formulation injection.serum oxytetracycline pharmacokinetics were studied in 18 african elephant (loxodonta africana) calves. each elephant received separate injections of oxytetracycline at approximately 18 mg/kg i.m. and 8 mg/kg i.v. in a cross-over study. blood samples were drawn at 0, 24, 48, 72, and 96 hr postinjection. an additional sample was drawn 110 hr before the animals were reinjected in the cross-over study and a final blood sample was drawn 48 hr after the second dose. no lameness or stiffness was obser ...200010884122
unusually extensive networks of vocal recognition in african elephants.research on acoustic communication has often focused on signalling between territorial individuals or static neighbouring groups. under these circumstances, receivers have the opportunity to learn to recognize the signals only of the limited number of conspecifics with which they are in auditory contact. in some mammals, however, social units move freely with respect to one another and range widely, providing individuals with opportunities to learn to recognize the signals of a wide range of con ...200010877888
signals and assessment in african elephants: evidence from playback experiments.a series of playback experiments using two elephant vocalizations, the 'musth rumble' and the 'oestrous call', was carried out in amboseli national park to examine signalling and assessment in african elephants, loxodonta africana. in response to the musth rumble of a high-ranking male other musth males approached the speaker aggressively, whereas nonmusth males walked away from the stimulus. the call of an oestrous female, too, attracted musth males who approached the speaker rapidly, while non ...199910413556
patterns of urinary and fecal steroid excretion during the ovarian cycle and pregnancy in the african elephant (loxodonta africana).the aims of the present study were to (i) determine the relative abundance of the 5alpha-reduced progestins 5alpha-pregnane-3-ol-20-one (5alpha-p-3oh) and 5alpha-dihydroprogesterone (5alpha-dhp) and progesterone (p4) in african elephant feces and to establish improved fecal progestin assays for monitoring ovarian function; and (ii) describe longitudinal profiles of urinary and fecal progestin and estrogen metabolites during pregnancy. matched urine and fecal samples were collected weekly from si ...199910375466
serum prolactin concentrations in the captive female african elephant (loxodonta africana): potential effects of season and steroid hormone interactions.research was conducted to determine whether seasonal changes in prolactin secretion occur in nonpregnant female african elephants and to examine potential functional interrelationships between secretion of prolactin, cortisol, and progesterone. weekly blood samples were taken for 18 months from four female african elephants and the sera were analyzed by ria for progesterone, cortisol, and prolactin concentrations. there was no significant effect of season on serum concentrations of prolactin. es ...199910208775
histo- and cytophysiology of the lactating mammary gland of the african elephant (loxodonta africana).the lactating mammary gland of the african elephant (loxodonta africana) has been studied with a panel of morphological techniques focusing on (1) the functional changes during the secretory process, (2) proliferative process [by application of proliferating cell nuclear antigen (pcna) immunohistochemistry] and apoptotic phenomena [by use of the tunel technique] in the individual lobules, and (3) components of milk and milk-fat-globule membrane. in the lactating gland, the lobules are variably d ...19989799466
isolation and characterization of microsatellite loci in the african elephant, loxodonta africana. 19989787454
geographic variations in the composition of ivory of the african elephant (loxodonta africana).tracing the source of origin of illegal ivory will contribute to the identification of poorly managed game parks and facilitate steps taken to prevent the african elephant from becoming extinct. this study was aimed at establishing a database on the composition of ivory obtained from elephant sanctuary areas in southern africa. fragments of elephant ivory from seven geographically distinct areas in south africa, namibia and botswana were analysed for inorganic and organic content. a total of 20 ...19989758047
influence of gestation on uterine endometrial steroid receptor concentrations in the african elephant, loxodonta africana.the modulatory effects of gestational age and circulating concentrations of progesterone, 5alpha-pregnane-3,20-dione, and estradiol-17beta on the uterine sex steroid hormone receptor levels of the african elephant were investigated. uterine tissue biopsies and blood samples were obtained from animals culled in the kruger national park. estrogen and progesterone receptor concentrations were determined in uterine biopsies from subadult, lactating, early-, mid-, and late-pregnant elephants, by equi ...19989472923
ligand specificity of uterine oestrogen and progesterone receptors in the subadult african elephant, loxodonta africana.the ligand specificity of progesterone and oestrogen receptors in the uteri of four nonpregnant, nonlactating african elephants, killed during routine culling in the kruger national park, were determined. the mean (+/-sem) kd values of the oestrogen (0.18 +/- 0.019 x 10(-9) mol l-1, n = 12) and progesterone (0.22 +/- 0.025 x 10(-9) mol l-1, n = 12) receptors were essentially similar when [3h]promegestone was used as radioligand in the progesterone receptor assays. however, when [3h]progesterone ...19979155728
concentrations of progesterone and the 5 alpha-reduced progestins, 5 alpha-pregnane-3,20-dione and 3 alpha-hydroxy-5 alpha-pregnan-20-one, in luteal tissue and circulating blood and their relationship to luteal function in the african elephant, loxodonta africana.the 5 alpha-reduced metabolites 5 alpha-pregnane-3,20-dione (5 alpha-dhp) and 3 alpha-hydroxy-5 alpha-pregnan-20-one (5 alpha-p-3 alpha-oh) are the principal progestins biosynthesized by the african elephant corpus luteum. the aim of the present study was to determine luteal and circulating concentrations of these 5 alpha-reduced progestins in relation to progesterone (p4) and to examine whether their measurement reflects corpus luteum function. ovarian (luteal) tissue (30 corpora lutea and 3 co ...19979047008
binding activity of 5alpha-reduced gestagens to the progestin receptor from african elephant (loxodonta africana).recent findings in the african elephant (loxodonta africana) indicate that the major progestins contained within and biosynthesized by corpora lutea are 5alpha-reduced metabolites and that progesterone is quantitatively of minor importance. the specific gestagenic action within the reproductive tract of elephants was determined by measurement of relative binding affinity of the respective progestins to the gestagen receptor extracted from elephant endometrium. the cytosol was incubated with 40 n ...19979038248
a practical anesthesia monitoring protocol for free-ranging adult african elephants (loxodonta africana).twenty free-ranging adult african elephants (loxodonta africana) in northern botswana were immobilized with a mean (+/- sd) of 9.5 +/- 0.5 mg etorphine hydrochloride and 2,000 iu hyaluronidase by intramuscular (im) dart. the mean time to recumbency was 8.7 +/- 2.4 min. all animals were maintained in lateral recumbency. the anesthesia monitoring protocol included cardiothoracic auscultation; palpation of auricular pulse for quality and regularity; checking of rectal temperature, and monitoring of ...19979027693
the osteology of the african elephant (loxodonta africana): vertebral column, ribs and sternum.the vertebral column, sternum and ribs of the african elephant were studied and illustrated. in the cervical series, the vertebrae are characterized by very short (compressed) vertebral bodies and short spinous processes. there are 20-21 thoracic vertebrae that carry ribs, and three lumbar vertebrae. the neural arches of the five sacral vertebrae fuse with each other as well as with the wings of the ilium, while the intervertebral discs do not ossify and the vertebral bodies remain separate. the ...19968856763
excretory fate of estradiol and progesterone in the african elephant (loxodonta africana) and patterns of fecal steroid concentrations throughout the estrous cycle.we developed and validated a noninvasive method to quantify fecal estrogens and progestins as a tool for monitoring long-term ovarian activity in free-ranging african elephants. the lag times between iv injection of [(3)h]estradiol and [(14)c]progesterone and peak excretion of radioactivity in urine and feces were approximately 4 hr and 48 hr, respectively. the majority of progesterone metabolites recovered was excreted in feces (55%) versus urine (45%), whereas comparatively little of the recov ...19968998970
the skull and mandible of the african elephant (loxodonta africana).in the present study the bones of the skull, excluding the hyoid apparatus, are described. all the bones are aerated by sinuses. in the occipital bone the squamous part is aerated from the sinus of the parietal bone, the lateral part is aerated from the tympanic bulla and the basal part from the sinus of the basisphenoid bone. condylar foramens and hypoglossal canals are absent. a small interparietal bone is present at birth. at an early age it fuses with the surrounding cranial bones. the squam ...19958668323
morphology of the deciduous tusk (tush) of the african elephant (loxodonta africana).the tusk of the african elephant is preceded by a deciduous tooth generally known as the tush. tushes from nine elephant fetuses and six calves younger than 1 year were exposed by dissection and described morphologically. all tushes consisted of a crown, root and pulpal cavity, the formation of which is completed soon after birth. they reached a maximum length of 5 cm, appeared not to erupt through the skin and were pushed aside and resorbed during enlargement of the distally located primordium ...19957677604
suspected cardiac glycoside poisoning in elephants (loxodonta africana).two young (< 2 years old) elephants (loxodonta africana) died suddenly and simultaneously at ongava game reserve bordering on the etosha national park, namibia. both elephants showed lung congestion, epi- and endocardial haemorrhages and hyperaemic areas in the mucosa of the stomach and small intestine. histopathology of the myocardium showed multifocal degeneration and necrosis of muscle fibres accompanied by haemorrhages. parts of the leaves of the alien plant cryptostegia grandiflora (asclepi ...19947602572
arterial blood pressure of the african elephant (loxodonta africana) under etorphine anaesthesia and after remobilisation with diprenorphine. 19947863595
progestin content and biosynthetic potential of the corpus luteum of the african elephant (loxodonta africana).the aim of this study was to examine the progestin content and biosynthetic potential of the corpus luteum of the african elephant (loxodonta africana). luteal tissue was collected from nonpregnant and early, mid- and late pregnant elephants (n = 2 per group) shot in the kruger national park. pieces of individual corpora lutea (2-3 per animal; 23 in total) were stored directly in ethanol before hormone analysis. matching tissue pieces were incubated for 2 h with [3h]pregnenolone (2 x 10(5) c.p.m ...19947799309
a histocytochemical study of mucus glycoproteins or mucins in the intestinal tract of the african elephant (loxodonta africana).the distribution of neutral mucins, sialomucins and sulphomucins was determined histochemically in the duodenum, jejunum, ileum and colon of the african elephant (loxodonta africana). the techniques used were periodic acid-schiff (pas), alcian blue/periodic acid-schiff (ab-pas), high-iron-diamine/alcian blue (hid-ab), alcian blue at varying ph solutions and alcian blue at high temperature after methylation and saponification. acid mucins appear to dominate neutral mucins, the latter decreasing t ...19947596568
osteology of the pelvic limb of the african elephant (loxodonta africana).the pelvic girdle was characterized by large, transversely-placed ilial wings. the femur was the longest bone of the skeleton and its fovea capitis was situated caudomedially between the epiphyseal line and the articular surface of the femoral head. a wedge-shaped patella articulated with the femoral trochlea. the bones of the crus were approximately half as long as the femur and consisted of the sturdy tibia and slender fibula. the condyles of the tibia were concave and the femoro-tibial joint ...19947898898
effects of gnrh analogues on pituitary-testicular function in free-ranging african elephants (loxodonta africana).we tested the ability of several gnrh analogues to suppress pituitary-testicular activity and potentially musth in free-ranging african elephants (loxodonta africana). in study 1, adult bulls were given 4 or 12 mg gnrh antagonist (detirelix) or saline i.m. on day 0 (n = 3 bulls per treatment). animals were then recaptured on day 2 (about 48 h later) and given 300 micrograms gnrh i.v. to assess the ability of the antagonist to block pituitary activity. detirelix reduced (p < 0.05) basal concentra ...19938107048
osteology of the thoracic limb of the african elephant (loxodonta africana).the forelimb bones of 8 elephants (7 adults, 1 juvenile) were studied. in addition, the bones of the digits were dissected and studied in situ in a mature specimen. the scapula, humerus and bones of the antebrachium (particularly the ulna) are massive in comparison to the short, relatively small bones of the manus. there are 8 carpal bones, 5 metacarpal bones and 5 digits. digits 2-4 consist of 3 phalanges each. the 5th digit consists of 2 phalanges, while the 1st is represented by a single phal ...19938332313
heat exchange by the pinna of the african elephant (loxodonta africana).1. surface temperatures of the pinnae of four female african elephants were measured at ambient temperatures between 14 and 32 degrees c using infrared thermography. instantaneous heat losses calculated using those values ranged from 10.67 to 76.2 w under the observed conditions. 2. using a value of 17 kcal/kg/day, those heat losses account for 0.65-4.64% of the animals' standard metabolic rates, considering one side of one ear only. 3. a model of heat flow across a flat vertical plate was const ...19921351443
odontoma in an african elephant (loxodonta africana).the first known case of an odontoma in an african elephant (loxodonta africana) is described. the tumour was fused with the coronal cementum of the sixth right mandibular molar tooth, thus preventing its eruption.19892634774
topography of the retina in the elephant loxodonta africana.the distribution of neurones in the ganglion cell layer of the retina of an african elephant is described. the eye was obtained post-mortem from an infant animal, which died of an unknown disease. it is assumed that most of the neurones observed in the ganglion cell layer are ganglion cells. ganglion cells concentrate along a horizontal axis extending across the retina inferior to the optic disc, as in the visual streak described in the retina of many mammals. they also concentrate in the upper ...19892819413
parotid salivary gland of the african elephant (loxodonta africana): structure and composition of saliva.specimens from parotid salivary glands of full-grown elephant (loxodonta africana) a (n=6) and saliva aspirated from their main excretory ducts were examined macroscopically and microscopically and analyzed biochemically. the composition of the saliva was compared to that of the blood. the parotids (n=12; mean = 7.4 kg) are homocrine and of a seromucous nature. myoepithelial cells are well-developed along intercalated ducts and their processes extend to proximal portions of allied acini. the sal ...19883210214
anatomy of the reproductive tract of the female african elephant (loxodonta africana) with reference to development of techniques for artificial breeding.complete reproductive tracts of 30 female african elephants (5-53 years), obtained during a population reduction procedure, were examined. the reproductive tracts were palpated in situ via the urogenital canal. a plastic speculum (1.3 x 170 cm) was introduced into the canal and dye was injected to simulate the procedure for artificial insemination. the lengths of reproductive tracts (from the vulva to the ovary) ranged from 120 to 358 cm. the length increased with the size and age of the animal. ...19883199367
short and long phases of progesterone secretion during the oestrous cycle of the african elephant (loxodonta africana).serum samples were collected from 3 mature female african elephants once each week for 15-18 months. circulating concentrations of progesterone, oestradiol and lh were determined by radioimmunoassay (ria). the lh ria was validated by demonstrating parallel cross-reaction with partly purified elephant lh pituitary fractions. changing serum progesterone concentrations indicated an oestrous cycle length of 13.3 +/- 1.3 weeks (n = 11). the presumed luteal phase, characterized by elevated serum proge ...19883184054
acute myocarditis in a captive african elephant (loxodonta africana). 19873820423
influence of cryoprotective diluent on post-thaw viability and acrosomal integrity of spermatozoa of the african elephant (loxodonta africana).electroejaculates from free-ranging, african elephants were frozen to test various seminal diluents, freezing methods and thawing media on post-thaw sperm viability and structural integrity. in study i, each ejaculate was tested with each of 7 cryoprotective diluents. after cooling to 5 degrees c and equilibration on ice (4 degrees c) for 120 min, each aliquant was pellet frozen on solid co2, stored in liquid nitrogen and thawed (37 degrees c) in saline or tissue culture solution. amongst all di ...19863531508
electroejaculation, semen characteristics and serum testosterone concentrations of free-ranging african elephants (loxodonta africana).a regimented electroejaculation protocol (120 electrical stimulations; 10-30 v) was used to collect semen and characterize ejaculate quality from 9 adult, free-ranging african elephants under anaesthesia. eight of the 9 ejaculates contained high concentrations of progressively motile spermatozoa. the overall mean ejaculate volume, sperm concentration/ml ejaculate, sperm motility, sperm status and ejaculate ph were 93.3 ml, 2408.6 x 10(6) spermatozoa/ml, 70%, 3.9 and 7.4, respectively. a high per ...19846471047
musth and urinary testosterone concentrations in the african elephant (loxodonta africana).urine samples were obtained from free-ranging african elephants that were considered to be in and out of musth. testosterone concentrations, measured by radioimmunoassay were significantly greater in males that were in or around the time of behavioural musth. this study supports a correlation between the observed behavioural characteristics of musth and urinary testosterone levels.19846694143
circulating oestrogen concentrations during pregnancy in the african elephant (loxodonta africana).oestrone, oestradiol-17 beta and oestriol were measured in plasma samples from non-pregnant and pregnant african elephants shot in the wild. enzymic hydrolysis of plasma showed that approximately 90 and 96% of the total (i.e. conjugated plus unconjugated) concentrations of oestrone and oestradiol-17 beta, respectively were represented by conjugated hormones. unconjugated oestrogens remained low (less than 50 pg ml) in all samples, with no distinction between non-pregnant and pregnant animals. le ...19836822969
blood concentrations of gonadotrophins, prolactin and gonadal steroids in males and in non-pregnant and pregnant female african elephants (loxodonta africana).no seasonal variation in any of the hormones measured was apparent in males or females. testosterone levels in males increased around puberty (10-11 years) and remained significantly higher in adult than prepubertal males. this was not accompanied by any significant change in levels of lh, fsh or prolactin. in non-pregnant females there was no apparent difference in levels of lh, fsh or prolactin with age. there was a significant increase in progesterone around puberty (12 years) but there was c ...19836401810
constituents of temporal gland secretion of the african elephant,loxodonta africana.temporal gland secretion (tgs), obtained from 15 different mature african elephants in kruger national park was analyzed for volatile constituents. only five volatile components were present.p-cresol was present in all samples, but phenol was found as an appreciable component of only one sample and as trace amounts in six others. three sesquiterpenes were identified, the latter two being new natural products:e-farnesol, farnesol hydrate (3,7,11-trimethyl-2,10-dodecadien-1,7-diol), and farnesol d ...198224415180
studies of the deferent ducts from the testis of the african elephant, loxodonta africana. iii. ultrastructure and cytochemistry of the ductuli efferentes.the epithelium of the ductuli efferentes is composed of ciliated, principal, halo and basal cells. the supranuclear cytoplasm of ciliated cells is penetrated by particularly long cilial rootlets which are surrounded by numerous elongate mitochondria. microtubules are arranged along the longitudinal axis of the cells. the spaces between the microvilli of principal cells form canaliculi which penetrate the apical cytoplasm and appear to be involved in endocytotic activity. the supranuclear cytopla ...19816277838
musth in the african elephant, loxodonta africana. 19817266649
studies of the deferent ducts from the testis of the african elephant, loxodonta africana. i. structural differentiation. 19817298489
luminal composition and maturation of spermatozoa in the genital ducts of the african elephant (loxodonta africana).the mean spermatocrit and sodium, potassium and protein concentrations of fluid collected from the rete testis of the elephant were similar to values described for the ram. sperm maturation, as assessed by the location of the cytoplasmic droplet in the middle pice, occurred in the distal head and the isthmus of the epididymis (middle segment). spermatocrit determinations indicated that 96% of the fluid leaving the testis was reabsorbed by the efferent ducts and proximal initial segment, and 53% ...19807431332
studies of the deferent ducts from the testis of the african elephant, loxodonta africana. ii. histochemistry of the epididymis.the three main segments of the elephant epididymis were examined for the occurrence, in the spermatozoa and lining epithelium, of carbohydrates, neutral lipids and phospholipids, atpase, alkaline phosphatase, succinic dehydrogenase, glucose-6-phosphate dehydrogenase, diaphorases, hydroxysteroid dehydrogenases, acid phosphatase and non-specific esterase. the most distinct feature of the carbohydrate content of the epididymis was a layer of acidic, alcian blue-positive glycoprotein over the lumina ...19806447136
dislocation of the elbow and its social consequences for an african elephant.a dislocated elbow of a male elephant calf (loxodonta africana) in the addo elephant national park resulted in it being harassed by other elephants and consequently leaving its maternal herd at the age of 6 years, rather than the more usual age of 9-10 years. in the absence of large predators the elephant had survived for 9 years and had adapted its locomotion and intraspecific behaviour to its injury. the humeral joint of the affected forelimb was carried in partial extension while the cubital ...1979551180
blood characteristics of the african elephant (loxodonta africana cyclotis).mean corpuscular volume, hematocrit, hemoglobin concentration and red and white cell counts from five domesticated african elephants were measured. the results obtained are tabulated and compared with those from shot and chemically immobilized african elephants.1979459036
serum calcium, magnesium, phosphorus and alkaline phosphatase in the african elephant, loxodonta africana. 1977830482
proceedings: the glycerylphosphorylcholine and phospholipid pattern of the genital duct and spermatozoa of the african elephant, loxodonta africana. 19761255600
detection of oestrus in the african elephant (loxodonta africana). 19751241771
arteriosclerosis in the african elephant: part 2. medial sclerosis.a type of spontaneous arteriosclerosis, described as medial sclerosis and quite distinct from atherosclerosis, was found in the aortas, coronary arteries and aortic branch arteries of free-living elephants (loxodonta africana) in uganda and kenya. the lesions took the form of calcified fibrotic plaques in the inner tunica media. the calcification appeared to commence in the internal elastic lamina and was associated with atrophy of medial smooth muscle fibres and their replacement by fibrous tis ...20141131300
implantation, foetal membranes and early placentation of the african elephant, loxodonta africana. 19744154465
spermatozoa in the genital ducts of the african elephant, loxodonta africana. 19744431010
[the epiphysis and the circumventricular structures of the epithalamus in the brain of the elephant (loxodonta africana)]. 19725042251
the functional significance of movements and positions of the pinnae of the african elephant, loxodonta africana. 19715545560
[karyotype and sex chromatin of the african elephant (loxodonta africana)]. 19705474735
observations on arteriosclerosis, serum cholesterol and serum electrolytes in the wild african elephant (loxodonta africana). 19705461445
biochemical observations on the corpora lutea of the african elephant, loxodonta africana. 19695357935
[brain development and morphology in a proboscidian, the african elephant (loxodonta africana blum.)]. 19694987411
occurrence of placental scars in the uterus of the african elephant (loxodonta africana). 19676066501
male reproductive organs of the african elephant, loxodonta africana. 19676029179
the testis of the african elephant (loxodonta africana). i. histological features. 19676066825
the testis of the african elephant (loxodonta africana). ii. development, puberty and weight. 19676066777
biochemical and histological observations on the corpora lutea of the african elephant, loxodonta africana. 196514257719
[research on brain of african elephant (loxodonta africana blum). iii. the subfornical organ]. 195613381444
[research on brain of african elephant (loxodonta africana blum). ii. the hypothalamus]. 195613381443
[research on brain of african elephant (loxodonta africana blum). i. introduction and macroscopic considerations]. 195613381442
[form of the brain of elephant (loxodonta africana blum.) during prenatal life]. 195413161223
reproduction of the african elephant, loxodonta africana. 195114888793
a comparative perspective on the evolution of mammalian reactions to dead conspecifics.in a variety of mammalian species, mothers and others care for and/or carry deceased newborns, and sometimes other conspecifics. the rationale for such behavior remains elusive. based upon field observations of olive baboon (papio anubis), african elephant (loxodonta africana), and thornicroft's giraffe (giraffa camelopardalis) responses to recently dead conspecifics, combined with reports in the literature, a hypothesis is proposed to account for this activity. among female mammals, lifetime re ...202030895413
accurate sex identification of ancient elephant and other animal remains using low-coverage dna shotgun sequencing data.sex identification of ancient animal biological remains can benefit our understanding of historical population structure, demography and social behavior. traditional methods for sex identification (e.g., osteological and morphometric comparisons) may be ineffective when animal remains are not well preserved, when sex distinguishing characteristics have not yet developed, or where organisms do not exhibit sex-associated phenotypic dimorphisms. here we adapt a method developed for human sex determ ...202032107273
the xpert mtb/rif ultra assay detects mycobacterium tuberculosis complex dna in white rhinoceros (ceratotherium simum) and african elephants (loxodonta africana).the study describes the novel use of the xpert mtb/rif ultra assay for detection of mycobacterium tuberculosis complex (mtbc) dna in samples from white rhinoceros (ceratotherium simum) and african elephants (loxodonta africana). culture negative respiratory sample matrices were spiked to determine if the ultra could detect mtbc dna in rhinoceros and elephant samples. rhinoceros bronchial alveolar lavage fluid (balf) was found to have an inhibitory effect on the ultra. in this study, the limit of ...202032879401
ovarian cyclicity and prolactin status of african elephants (loxodonta africana) in north american zoos may be influenced by life experience and individual temperament.hyperprolactinemia is an endocrine disorder associated with infertility in many species, including elephants. in a recent survey of zoos accredited by the association of zoos and aquariums (aza), over half of african elephant females (n = 101) were not cycling normally, 30% of which exhibited hyperprolactinemia. we examined whether life experience and temperament predict ovarian cyclicity and circulating prolactin status in individual african elephant females. we hypothesized that, similar to hu ...202032531397
contagious yawning in african elephants (loxodonta africana): responses to other elephants and familiar humans.while spontaneous yawning is common across all vertebrate classes, contagious yawning is less common and has been observed only in a few species of social animals. interspecific contagious yawning in response to yawning by humans has been observed only by chimpanzees and dogs. after confirming additional occurrences of intraspecific contagious yawning in a group of captive african elephants previously studied, we further investigated the potential for the same group of elephants to engage in int ...202032457923
wildlife impacts and vulnerable livelihoods in a transfrontier conservation landscape.interactions between humans and wildlife resulting in negative impacts are among the most pressing conservation challenges globally. in regions of smallholder livestock and crop production, interactions with wildlife can compromise human well-being and motivate negative sentiment and retaliation toward wildlife, undermining conservation goals. although impacts may be unavoidable when human and wildlife land use overlap, scant large-scale human data exist quantifying the direct costs of wildlife ...202032406981
fatal tuberculosis in a free-ranging african elephant and one health implications of human pathogens in wildlife.tuberculosis (tb) in humans is a global public health concern and the discovery of animal cases of mycobacterium tuberculosis (mtb) infection and disease, especially in multi-host settings, also has significant implications for public health, veterinary disease control, and conservation endeavors. this paper describes a fatal case of mtb disease in a free-ranging african elephant (loxodonta africana) in a high human tb burden region. necropsy revealed extensive granulomatous pneumonia, from whic ...201930788347
a multispecies assessment of wildlife impacts on local community livelihoods.conflicts between the interests of agriculture and wildlife conservation are a major threat to biodiversity and human well-being globally. addressing such conflicts requires a thorough understanding of the impacts associated with living alongside protected wildlife. despite this, most studies reporting on human-wildlife impacts and the strategies used to mitigate them focus on a single species, thus oversimplifying often complex systems of human-wildlife interactions. we sought to characterize t ...202032496643
can an herbivore affect where a top predator kills its prey by modifying woody vegetation structure?in large mammal communities, little is known about modification of interspecific interactions through habitat structure changes. we assessed the effects of african elephants (loxodonta africana) on features of woody habitat structure that can affect predator-prey interactions. we then explored how this can influence where african lions (panthera leo) kill their prey. indeed, lions are stalk-and-ambush predators and habitat structure and concealment opportunities are assumed to influence their hu ...202032060732
serum health biomarkers in african and asian elephants: value ranges and clinical values indicative of the immune response.serum biomarkers indicative of inflammation and disease can provide useful information regarding host immune processes, responses to treatment and prognosis. the aims of this study were to assess the use of commercially available anti-equine reagents for the quantification of cytokines (tumor necrosis factor-alpha (tnf-α), interferon-gamma (ifn-γ), interleukins (il) 2, 6, and 10) in african (loxodonta africana, n = 125) and asian (elephas maximus, n = 104) elephants, and alongside previously val ...202032992555
noninvasive sampling for detection of elephant endotheliotropic herpesvirus and genomic dna in asian (elephas maximus) and african (loxodonta africana) elephants.elephant endotheliotropic herpesvirus (eehv) hemorrhagic disease (eehv-hd) threatens asian elephant (elephas maximus) population sustainability in north america. clusters of cases have also been reported in african elephants (loxodonta africana). risk to range country elephant populations is unknown. currently, eehv detection depends upon sampling elephants trained for invasive blood and trunk wash collection. to evaluate noninvasive sample collection options, paired invasively collected (blood, ...202032549575
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