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endocrinology of the ovarian cycle and pregnancy in the asian (elephas maximus) and african (loxodonta africana) elephant.in reviewing the literature, this paper assesses the current level of understanding of the hormonal control of the ovarian cycle and pregnancy in the elephant. data are compiled from two genera, elephas maximus and loxodonta africana, recognizing differences where known to exist. measurements of various steroid and peptide hormones, but most notably immunoreactive progesterone (ip), indicate an overall cycle length of 15-16 weeks, comprising an 8-11-week luteal phase and a shorter inter-luteal ( ...19989835363
chemical signals in the reproduction of asian (elephas maximus) and african (loxodonta africana) elephants.asian (elephas maximus) and african (loxodonta africana) elephants exhibit polygynous mating that involves female choice of mates and male-male competition for access to females. chemical signals mediate intersexual and intrasexual interactions associated with reproduction. the need for reliable and honest signals is accentuated by the markedly different social structure of adult males and females. adult female elephants live in matriarchal herds consisting of a dominant female and several gener ...19989835364
antral follicles develop in xenografted cryopreserved african elephant (loxodonta africana) ovarian tissue.the preservation of germ plasm from endangered species could augment captive breeding programs aimed at maintaining genetic diversity. mammalian female germ plasm (oocytes) is extremely difficult to collect and cryopreserve; however, a promising alternative is the cryopreservation of ovarian tissue. in the present study, athymic nude (nu/nu) balb/c mice were used to evaluate in vivo viability of cryopreserved ovarian tissue from institute of cancer research genotype (icr) mice or elephants. fema ...19989835381
fundamental cryobiology of selected african mammalian spermatozoa and its role in biodiversity preservation through the development of genome resource banking.fundamental cryobiological characteristics of spermatozoa from threatened or endangered species must be determined for successful cryopreservation techniques to be established. in this study, spermatozoa from four diverse species, impala (aepyceros melampus), wart hog (phacochoerus aethiopicus), elephant (loxodonta africana), and lion (panthera leo), were collected by electroejaculation or epididymal aspiration. spermatozoal plasma membrane permeability to water (hydraulic conductivity, lp) and ...19989835382
histogenesis of the chequered pattern of ivory of the african elephant (loxodonta africana).this study aimed to propose a hypothesis on the events which lead to the development of the characteristic chequered pattern of elephant ivory. twenty fragments of ivory and six elephant tusks were obtained through the national parks board of south africa. polished surfaces were prepared in sagittal and longitudinal planes and the characteristics of the distinctive chequered pattern described. light- and electron-microscopical techniques and image analyses were employed to determine the morpholo ...19989877328
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
prevalence of toxoplasma gondii antibodies in sera of domestic pigs and some wild game species from zimbabwe.serum samples of domestic pigs (sus scrofa), elands (taurotragus oryx), sable antelopes (hippotragus niger), warthogs (phacochoerus aethiopicus), bushpigs (koiropotamus [potamochoerus] koiropotamus), white rhinos (ceratotherium simus), african buffalos (syncerus caffer), wildebeest (connochaetas taurinus), and african elephants (loxodonta africana) from zimbabwe were tested for toxoplasma gondii igg antibodies by the modified agglutination test (mat) with whole formalized tachyzoites and mercapt ...199910219323
the developing renal, reproductive, and respiratory systems of the african elephant suggest an aquatic ancestry.the early embryology of the elephant has never been studied before. we have obtained a rare series of african elephant (loxodonta africana) embryos and fetuses ranging in weight from 0.04 to 18.5 g, estimated gestational ages 58-166 days (duration of gestation is approximately 660 days). nephrostomes, a feature of aquatic vertebrates, were found in the mesonephric kidneys at all stages of development whereas they have never been recorded in the mesonephric kidneys of other viviparous mammals. th ...199910318922
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
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
clinical and pathological findings of a newly recognized disease of elephants caused by endotheliotropic herpesviruses.the unique clinical and pathological findings in nine asian (elephas maximus) and two african (loxodonta africana) elephants from north american zoos with a highly fatal disease caused by novel endotheliotropic herpesviruses are described. identification of the viruses by molecular techniques and some epidemiological aspects of the disease were previously reported. consensus primer polymerase chain reaction (pcr) combined with sequencing yielded molecular evidence that confirmed the presence of ...200010682740
contraceptive potential of the porcine zona pellucida vaccine in the african elephant (loxodonta africana).immunocontraception has been successful in controlling free-roaming equids; however, what is the potential for the immunocontraceptive control of the african elephant (loxodonta africana)? the porcine zona pellucida (pzp) glycoproteins share antigenic domains with the african elephant zona pellucida (elzp) glycoproteins, and anti-zona pellucida serum antibodies have been successfully stimulated. to determine the cross-reactivity of the pzp and elzp, immunocytochemistry was evaluated by light and ...199910735124
mitochondrial dna variation, phylogeography and population structure of the asian elephant.we report the first genetic analysis of free-ranging asian elephants (elephas maximus). we sampled 118 elephants from sri lanka, bhutan/north india, and laos/vietnam by extracting dna from dung, pcr amplifying and sequencing 630 nucleotides of mitochondrial dna, including part of the variable left domain of the control region. comparison with african elephant (loxodonta africana) sequences indicated a relatively slow molecular clock in the proboscidea with a sequence divergence of approximately ...200010762406
etorphine-halothane anaesthesia in two five-year-old african elephants (loxodonta africana).anaesthesia of 2 five-year-old female african elephants (loxodonta africana) was required for dental surgery. the animals were each premedicated with 120 mg of azaperone 60 min before transportation to the hospital. before offloading, 1 mg etorphine was administered intramuscularly (i.m.) to each elephant to facilitate walking them to the equine induction/recovery room. for induction, 2 mg etorphine was administered i.m. to each animal. induction was complete within 6 min. surgical anaesthesia w ...199910855842
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
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
polymorphic microsatellite dna loci identified in the african elephant (loxodonta africana). 200010886668
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
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
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
evaluation of a multiple-antigen enzyme-linked immunosorbent assay for detection of mycobacterium tuberculosis infection in captive elephants.mycobacterium tuberculosis has become an important agent of disease in the captive elephant population of the united states, although current detection methods appear to be inadequate for effective disease management. this investigation sought to validate a multiple-antigen enzyme-linked immunosorbent assay (elisa) for screening of m. tuberculosis infection in captive elephants and to document the elephant's serologic response over time using a cross-sectional observational study design. serum s ...200011237135
an overview of the central nervous system of the elephant through a critical appraisal of the literature published in the xix and xx centuries.the two species of elephants (indian: elephas maximus and african: loxodonta africana) possess the largest brain among land mammals. due to its size, the elephant brain is discussed in virtually every paper dealing with the evolution of the central nervous system of mammals and comparative brain size. studies on the social habits of elephants also deal with the skills and the "intelligence" and brain size of these species. yet most of the descriptions and conclusions reported in comparative stud ...200111275412
matriarchs as repositories of social knowledge in african elephants.despite widespread interest in the evolution of social intelligence, little is known about how wild animals acquire and store information about social companions or whether individuals possessing enhanced social knowledge derive biological fitness benefits. using playback experiments on african elephants (loxodonta africana), we demonstrated that the possession of enhanced discriminatory abilities by the oldest individual in a group can influence the social knowledge of the group as a whole. the ...200111313492
application of an enzyme-immunoassay (eia) for rapid screening of 5 alpha-pregnane-3,20-dione (dhp) in blood plasma of the asian elephant, elephas maximus.populations of african (loxodonta africana) and asian elephants (elephas maximus) in zoos and safari parks are at risk due to their low reproductive success. to extend the limited knowledge of their reproductive physiology, the development of easy and practical methods for the analysis of the relevant reproductive hormones is essential to support e.g. assisted reproduction. for the measurement of 5 alpha-pregnane-3,20-dione (dhp), the predominant ovarian gestagen in both species, an enzyme-immun ...200111413705
a variant of the endotheliotropic herpesvirus in asian elephants (elephas maximus) in european zoos.newly discovered, lethal elephant endotheliotropic herpesviruses (eehv) have been identified in both asian (elephas maximus) and african (loxodonta africana) elephants. carried by otherwise healthy african elephants they can be fatal mainly for young asian elephants. since zoos often harbour both elephant species, we conducted a survey on the presence of eehv in asian elephants from 12 european zoos, 3 circuses and 1 israeli zoo. here, we demonstrate that all eehv that have affected asian elepha ...200111423201
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
comparative cytogenetics of the african elephant (loxodonta africana) and asiatic elephant (elephas maximus).g- and c-banded karyotypes of the two extant species of the mammalian order proboscidea are presented for the first time. chromosome complements were 2n = 56 in both loxodonta africana and elephas maximus. comparisons between the species demonstrated a high level of chromosome band homology, with 26 conserved autosomal pairs. the normal diploid karyotype of l. africana had 25 acrocentric/telocentric and two metacentric/submetacentric autosomal pairs. e. maximus differed by having one less acroce ...200111528120
clostridium perfringens beta2-toxin in an african elephant (loxodonta africana) with ulcerative enteritis.a 22-year-old female african elephant (loxodonta africana) developed diarrhoea of unknown cause which lasted for two days. the animal was euthanased after it remained recumbent and refused to get up. gross pathological changes were present mainly in the gastrointestinal tract. the intestinal contents were watery and dark brown. several areas of the mucosa of the small intestine were covered minimally to moderately with fibrin and had a few 0.1 x 10 to 15 cm linear ulcerations. microscopical lesi ...200111761293
pharmacokinetics and effects of succinylcholine in african elephant (loxodonta africana) and impala (aepyceros melampus).the phenomenon of slow onset of succinylcholine (sch) effect in elephants was investigated by analyzing blood concentrations of sch and its metabolite choline in elephant and impala. to assess whether the slow onset phenomenon is related to the pharmacokinetics of sch following i.m. administration, we analyzed the time course of plasma concentrations of intact drug and its metabolite and determined its pharmacological effects. blood samples were obtained from anaesthetized elephant (n=6) and imp ...200211923057
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
the properties of geophysical fields and their effects on elephants and other animals.geophysical properties of acoustic, seismic, electric, and magnetic waveforms create opportunities and constraints for animals' communication and sensory monitoring of the environment. the geometric spreading of waves differs; at some frequencies, transmission is most efficient and has minimal noise. the spreading properties of seismic waves favor long-distance propagation for communication and environmental monitoring, and would benefit elephants (elephas maximus and loxodonta africana), such a ...200212083604
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
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
field applications of immunocontraception in african elephants (loxodonta africana).the primary aim of the makalali elephant immunocontraception programme is to test the efficacy of porcine zona pellucida (pzp) vaccine for practical population control of elephants in small, enclosed reserves, with the goal of stabilizing the current growth rate and reducing it to the 5-10% per annum displayed currently in the kruger national park. a secondary aim is to test the hypothesis that pzp treatment does not affect patterns of elephant social behaviour. eighteen sexually mature cows (ag ...200212220151
dependence of population response to fertility control on the survival of sterile animals and their role in regulation.the species for which fertility control is presently used, or for which it is being developed, range from small mammal pests, such as the house mouse (mus domesticus), to large mammals, such as the african elephant (loxodonta africana). however, the possibility of a population response other than a reduction in abundance proportional to the fraction of animals rendered infertile has been shown in field trials. for example, when intermediate levels of sterility were imposed on wild populations of ...200212220168
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
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 lateral enamel lamina--component of tooth primordia in selected mammalian species.the lateral enamel lamina (lel) is a part of the enamel organ, which is probably not involved in tooth formation. it represents, besides the "stalk" of the tooth primordium, a second interconnection between enamel organ and oral epithelium or vestibular lamina. we detected the lel in the sheep (ovis aries), the dolphin (stenella attenuata), and the vole (microtus agrestis) by light microscopy and computer-aided three-dimensional reconstruction. the lel could be found in cap to bell stage tooth p ...200212494916
in vitro succinylcholine hydrolysis in plasma of the african elephant (loxodonta africana) and impala (aepyceros melampus).in elephants the time lapsed from i.m. injection of an overdose of the muscle relaxant succinylcholine (such) until death, is significantly longer than in impala. to determine a difference in the rate of such hydrolysis, once the drug enters the circulation, contributes to this phenomenon we have measured the rate of hydrolysis of such in elephant and impala plasma, and by elephant erythrocytes. rate of hydrolysis was determined by incubating such in plasma or erythrocyte lysate at 37 degrees c ...200312524024
mammary botryomycosis and mastectomy in an african elephant (loxodonta africana). 200312553584
hepatocellular endoplasmic reticulum storage disease in an african elephant (loxodonta africana).large intracytoplasmic inclusions were observed in hepatocytes of a 7-year-old african elephant (loxodonta africana). the inclusions were oval to polyhedral with either a homogeneous glassy or a granular appearance. they were positive for the periodic acid-schiff (pas) reaction. electron microscopical examination revealed that the inclusions consisted of granular material with moderate electron-density and were membrane-bounded. the findings suggested that the inclusions were derived from endopl ...200312634098
structure and presumptive function of the iridocorneal angle of the west indian manatee (trichechus manatus), short-finned pilot whale (globicephala macrorhynchus), hippopotamus (hippopotamus amphibius), and african elephant (loxodonta africana).the iridocorneal angles of prepared eyes from the west indian manatee, short-finned pilot whale, hippopotamus and african elephant were examined and compared using light microscopy. the manatee and pilot whale demonstrated capacity for a large amount of aqueous outflow, probably as part of a system compensating for lack of ciliary musculature, and possibly also related to environmental changes associated with life at varying depths. the elephant angle displayed many characteristics of large herb ...200312641841
mitochondrial cytochrome b of the lyakhov mammoth (proboscidea, mammalia): new data and phylogenetic analyses of elephantidae.the phylogenetic relationships between recent elephantidae (proboscidea, mammalia), that is to say extant elephants (asian and african) and extinct woolly mammoth, have remained unclear to date. the prevailing morphological scheme (mammoth grouped with asian elephant) is either supported or questioned by the molecular results. recently, the monophyly of woolly mammoths on mitochondrial grounds has been demonstrated (thomas, et al., 2000), but it conflicts with previous studies (barriel et al., 1 ...200312644401
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
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
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
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
plasma and erythrocyte fatty acids in captive asian (elephas maximus) and african (loxodonta africana) elephants.the fatty acid components of the plasma triglycerides and the phospholipid fractions of the red blood cells of a captive group of two african (loxodonta africana) and four asian (elephas maximus) elephants were investigated. all the animals received the same diet of hay, fruits and vegetables, and concentrates. a comparison with data from free-ranging african elephants or asian work-camp elephants showed that the captive elephants had lower proportions of polyunsaturated fatty acids (pufas), and ...200312885214
towards the delineation of the ancestral eutherian genome organization: comparative genome maps of human and the african elephant (loxodonta africana) generated by chromosome painting.this study presents a whole-genome comparison of human and a representative of the afrotherian clade, the african elephant, generated by reciprocal zoo-fish. an analysis of afrotheria genomes is of special interest, because recent dna sequence comparisons identify them as the oldest placental mammalian clade. complete sets of whole-chromosome specific painting probes for the african elephant and human were constructed by degenerate oligonucleotide-primed pcr amplification of flow-sorted chromoso ...200312965023
[form of the brain of elephant (loxodonta africana blum.) during prenatal life]. 195413161223
[fine structure of the temporal glands of african and indian elephants, loxodonta africana cuvier and elephas maximus linnaeus]. 195613381332
[research on brain of african elephant (loxodonta africana blum). i. introduction and macroscopic considerations]. 195613381442
[research on brain of african elephant (loxodonta africana blum). ii. the hypothalamus]. 195613381443
[research on brain of african elephant (loxodonta africana blum). iii. the subfornical organ]. 195613381444
biochemical and histological observations on the corpora lutea of the african elephant, loxodonta africana. 196514257719
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
reproduction of the african elephant, loxodonta africana. 195114888793
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
neural innervation of the tusk pulp of the african elephant (loxodonta africana). 200415074329
comparative endocrinology of cycling and non-cycling asian (elephas maximus) and african (loxodonta africana) elephants.up to 14% of asian and 29% of african elephants in captivity are not cycling normally or exhibit irregular cycles based on progestin profiles. to determine if ovarian acyclicity is related to other disruptions in endocrine activity, serum pituitary, thyroid, adrenal, and ovarian hormones in weekly samples collected for 6-25 months were compared between normal cycling (n=22 each species) and non-cycling (n=6 asian; n=30 african) elephants. a subset of cycling females (n=4 asian, 7 african) also w ...200415081836
oribatid mites as intermediate hosts of anoplocephala manubriata, cestode of the asian elephant in india.anoplocephala manubriata (cestoda: anoplocephalidae) is a tapeworm that parasitizes both african (loxodonta africana) and asian (elephas maximas) elephants. its life cycle has not yet been completely elucidated nor have intermediate hosts been previously reported. soil and substrate was collected in the kodanadu forest range, ernakulum district and guruvayur devaswom temple grounds, thrissur district, in kerala, india. oribatid mites (acari: oribatida) were collected from dung piles near captive ...200415139083
evaluation of post-thaw asian elephant (elephas maximus) spermatozoa using flow cytometry: the effects of extender and cryoprotectant.although the development of semen cryopreservation in the african elephants (loxodonta africana) has been accomplished, effective procedures for cryopreservation of asian elephant (elephas maximus) spermatozoa have not been established. in the present study, we investigate the freezing methods for conservation of asian elephant spermatozoa under field conditions and identify the most suitable freezing protocols which provide acceptable post-thaw semen quality. semen was collected from two asian ...200415226027
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
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
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 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
population pharmacokinetics of isoniazid in the treatment of mycobacterium tuberculosis among asian and african elephants (elephas maximus and loxodonta africana).we recently described the clinical presentation and treatment of 18 elephants from six herds infected with tb. treatment protocols and methods varied between herds to include both oral and rectal dosing using multiple drug doses and formulations. in this paper we present information regarding the pharmacokinetics (pk) of isoniazid (inh) in elephants and provide suggestions regarding initial treatment regimens. forty-one elephants received inh daily by either oral or rectal administration with di ...200515720511
automatic classification and speaker identification of african elephant (loxodonta africana) vocalizations.a hidden markov model (hmm) system is presented for automatically classifying african elephant vocalizations. the development of the system is motivated by successful models from human speech analysis and recognition. classification features include frequency-shifted mel-frequency cepstral coefficients (mfccs) and log energy, spectrally motivated features which are commonly used in human speech processing. experiments, including vocalization type classification and speaker identification, are pe ...200515759714
movements and corridors of african elephants in relation to protected areas.understanding how mammals satisfy their need for space in fragmenting ecosystems is crucial for ecosystem conservation. using state-of-the-art global positioning system (gps) technology we tracked 11 focal african elephants (loxodonta africana) in kenya at 3-hourly fix intervals and collected between 34 and 406 days per individual. our recordings gave a high spatio-temporal resolution compared to previous studies and allowed novel insights into range use. the actual ranges of the tracked elephan ...200515770465
seroprevalence of toxoplasma gondii in farm-reared ostriches and wild game species from zimbabwe.one hundred and seventy one serum samples from 10 game species from zimbabwe were tested for igg antibodies to toxoplasma gondii infection using the modified agglutination test (mat). significantly higher seroprevalences were found in the felidae (panthera leo) (92% of 26), bovidae (tragelaphus species) (55.9% of 34) and farm-reared struthionidae (struthio camelus) (48% of 50) compared to the other groups tested. among the bovidae, the nyala (tragelaphus angasii) had the highest seroprevalence o ...200515777687
elephants and human color-blind deuteranopes have identical sets of visual pigments.being the largest land mammals, elephants have very few natural enemies and are active during both day and night. compared with those of diurnal and nocturnal animals, the eyes of elephants and other arrhythmic species, such as many ungulates and large carnivores, must function in both the bright light of day and dim light of night. despite their fundamental importance, the roles of photosensitive molecules, visual pigments, in arrhythmic vision are not well understood. here we report that eleph ...200515781694
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
quantitative analysis of voltage-gated potassium currents from primary equine (equus caballus) and elephant (loxodonta africana) articular chondrocytes.in this comparative study, we have established in vitro models of equine and elephant articular chondrocytes, examined their basic morphology, and characterized the biophysical properties of their primary voltage-gated potassium channel (kv) currents. using whole cell patch-clamp electrophysiological recording from first-expansion and first-passage cells, we measured a maximum kv conductance of 0.15 +/- 0.04 ps/pf (n = 10) in equine chondrocytes, whereas that in elephant chondrocytes was signifi ...200515802557
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
physical, physiological, and behavioral correlates of musth in captive african elephants (loxodonta africana).although musth in male african elephants (loxodonta africana) is known to be associated with increased aggressiveness, urine dribbling (ud), temporal gland secretion (tgs), and elevated androgens, the temporal relationship between these changes has not been examined. here, we describe the pattern of musth-related characteristics in 14 captive elephant bulls by combining long-term observations of physical and behavioral changes with physiological data on testicular and adrenal function. the lengt ...200615957105
milk composition of a free-ranging african elephant (loxodonta africana) cow during early lactation.only one study previously reported comprehensively on the composition of african elephant's (loxodonta africana) milk that was collected from 30 dead animals. in the current study milk was obtained from a tame but free-ranging african elephant cow without immobilization during the period when she was 4-47 days postpartum. at the respective collection times the nutrient content was 21.8 and 25.0 g protein; 56.0 and 76.0 g fat; 71.1 and 26.0 g sugars per kilogram of milk. the protein fraction, res ...200515961336
[contribution of molecular phylogeny and morphometrics to the systematics of african elephants].african elephants are conventionally classified as a single species: loxodonta africana (blumenbach 1797). however, the discovery in 1900 of a smaller form of the african elephant, spread throughout the equatorial belt of this land, has given rise to a debate over the relevance of a second species of elephant in africa. the twentieth century has not provided any definite answer to this question. actually, recent molecular analyses have sustained this issue by advocating either a division of fore ...200415969338
population pharmacokinetics of pyrazinamide in elephants.this study was undertaken to characterize the population pharmacokinetics (pk), therapeutic dose, and preferred route of administration for pyrazinamide (pza) in elephants. twenty-three african (loxodonta africana) and asian (elephas maximus) elephants infected with or in contact with others culture positive for mycobacterium tuberculosis were dosed under treatment conditions. pza was dosed daily at 20-30 mg/kg via oral (fasting or nonfasting state) or rectal (enema or suppository) administratio ...200516207301
brain of the african elephant (loxodonta africana): neuroanatomy from magnetic resonance images.we acquired magnetic resonance images of the brain of an adult african elephant, loxodonta africana, in the axial and parasagittal planes and produced anatomically labeled images. we quantified the volume of the whole brain (3,886.7 cm3) and of the neocortical and cerebellar gray and white matter. the white matter-to-gray matter ratio in the elephant neocortex and cerebellum is in keeping with that expected for a brain of this size. the ratio of neocortical gray matter volume to corpus callosum ...200516216009
genomic inferences from afrotheria and the evolution of elephants.recent genetic studies have established that african forest and savanna elephants are distinct species with dissociated cytonuclear genomic patterns, and have identified asian elephants from borneo and sumatra as conservation priorities. representative of afrotheria, a superordinal clade encompassing six eutherian orders, the african savanna elephant was among the first mammals chosen for whole-genome sequencing to provide a comparative understanding of the human genome. elephants have large and ...200516226885
noninvasive genotyping and mendelian analysis of microsatellites in african savannah elephants.we obtained fresh dung samples from 202 (133 mother-offspring pairs) savannah elephants (loxodonta africana) in samburu, kenya, and genotyped them at 20 microsatellite loci to assess genotyping success and errors. a total of 98.6% consensus genotypes was successfully obtained, with allelic dropout and false allele rates at 1.6% (n = 46) and 0.9% (n = 37) of heterozygous and total consensus genotypes, respectively, and an overall genotyping error rate of 2.5% based on repeat typing. mendelian ana ...200516251516
placentation in the african elephant, loxodonta africana. iv. growth and function of the fetal gonads.the gonads, both ovaries and testes, of 44 elephant fetuses weighing 0.09-112 kg (6.1-21.3 months gestation) were examined grossly and histologically. as in equids, elephant fetal gonads undergo a phase of marked growth and enlargement during the second half of gestation, which is more pronounced in ovaries than testes due to growth and antrum formation of numerous follicles in the former. stromal cells undergo hypertrophy and transformation to form zones of interstitial cells that are associate ...200516264100
the fluidity of blood in african elephants (loxodonta africana).the large cellular volume of erythrocytes and the increased plasma concentration of proteins in elephants are factors which potentially affect blood rheology adversely. to verify blood rheology, routine hemorheologic variables were analyzed in four african elephants (loxodonta africana), housed in the zoo of vienna. whole blood viscosity at three different shear rates (wbv at low shear rate: wbv 0.7 s(-1) and wbv 2.4 s(-1); wbv at high shear rate: wbv 94 s(-1) done by ls30, contraves) and erythr ...200516317241
comparative anatomy of the ciliary body of the west indian manatee (trichechus manatus) and selected species.to examine the anatomy of the ciliary body in the west indian manatee (trichechus manatus), paying close attention to its vascularization and to compare to those of its distant relative, the african elephant (loxodonta africana), the amphibious hippopotamus (hippopotamus amphibius) and the aquatic short-finned pilot whale (globicephala macrorhynchus).200616359360
metagenomics to paleogenomics: large-scale sequencing of mammoth dna.we sequenced 28 million base pairs of dna in a metagenomics approach, using a woolly mammoth (mammuthus primigenius) sample from siberia. as a result of exceptional sample preservation and the use of a recently developed emulsion polymerase chain reaction and pyrosequencing technique, 13 million base pairs (45.4%) of the sequencing reads were identified as mammoth dna. sequence identity between our data and african elephant (loxodonta africana) was 98.55%, consistent with a paleontologically bas ...200616368896
stable isotopes in elephant hair document migration patterns and diet changes.we use chronologies of stable isotopes measured from elephant (loxodonta africana) hair to determine migration patterns and seasonal diet changes in elephants in and near samburu national reserve in northern kenya. stable carbon isotopes record diet changes, principally enabling differentiation between browse and tropical grasses, which use the c3 and c4 photosynthetic pathways, respectively; stable nitrogen isotopes record regional patterns related to aridity, offering insight into localized ra ...200616407164
the elephant knee joint: morphological and biomechanical considerations.elephant limbs display unique morphological features which are related mainly to supporting the enormous body weight of the animal. in elephants, the knee joint plays important roles in weight bearing and locomotion, but anatomical data are sparse and lacking in functional analyses. in addition, the knee joint is affected frequently by arthrosis. here we examined structures of the knee joint by means of standard anatomical techniques in eight african (loxodonta africana) and three asian elephant ...200616420379
complete mitochondrial genome and phylogeny of pleistocene mammoth mammuthus primigenius.phylogenetic relationships between the extinct woolly mammoth (mammuthus primigenius), and the asian (elephas maximus) and african savanna (loxodonta africana) elephants remain unresolved. here, we report the sequence of the complete mitochondrial genome (16,842 base pairs) of a woolly mammoth extracted from permafrost-preserved remains from the pleistocene epoch--the oldest mitochondrial genome sequence determined to date. we demonstrate that well-preserved mitochondrial genome fragments, as lo ...200616448217
the ties that bind: genetic relatedness predicts the fission and fusion of social groups in wild african elephants.many social animals live in stable groups. in contrast, african savannah elephants (loxodonta africana) live in unusually fluid, fission-fusion societies. that is, 'core' social groups are composed of predictable sets of individuals; however, over the course of hours or days, these groups may temporarily divide and reunite, or they may fuse with other social groups to form much larger social units. here, we test the hypothesis that genetic relatedness predicts patterns of group fission and fusio ...200616537121
myth, marula, and elephant: an assessment of voluntary ethanol intoxication of the african elephant (loxodonta africana) following feeding on the fruit of the marula tree (sclerocarya birrea).africa can stir wild and fanciful notions in the casual visitor; one of these is the tale of inebriated wild elephants. the suggestion that the african elephant (loxodonta africana) becomes intoxicated from eating the fruit of the marula tree (sclerocarya birrea) is an attractive, established, and persistent tale. this idea now permeates the african tourist industry, historical travelogues, the popular press, and even scholastic works. accounts of ethanol inebriation in animals under natural con ...200616555195
ovulation, pregnancy, placentation and husbandry in the african elephant (loxodonta africana).the african elephant reproduces so efficiently in the wild that overpopulation is now a serious problem in some game parks in zimbabwe, botswana and south africa. the female reaches puberty between 10 and 12 years of age in the wild and, when in captivity, shows oestrous cycles of 14-15 weeks duration. she readily conceives a singleton in the wild yet her uterus has the capacity for twins. she shows a gestation length of 22 months and, in the wild, shows a population density and feed dependent i ...200616627297
insect pheromones and precursors in female african elephant urine.using automated solid-phase dynamic extraction and gas chromatography-mass spectrometry, our search for urinary chemical signals from ovulatory female african elephants (loxodonta africana) has revealed the bark beetle aggregation pheromones frontalin, exo-brevicomin, and endo-brevicomin, as well as their precursors and the aphid alarm pheromones (e,e)-alpha-farnesene and (e)-beta-farnesene. enantiomeric ratios for brevicomins have been determined. prior discovery of common insect/elephant phero ...200616758337
elephant brain. part i: gross morphology, functions, comparative anatomy, and evolution.we report morphological data on brains of four african, loxodonta africana, and three asian elephants, elephas maximus, and compare findings to literature. brains exhibit a gyral pattern more complex and with more numerous gyri than in primates, humans included, and in carnivores, but less complex than in cetaceans. cerebral frontal, parietal, temporal, limbic, and insular lobes are well developed, whereas the occipital lobe is relatively small. the insula is not as opercularized as in man. the ...200616782503
generalized perceptual linear prediction features for animal vocalization analysis.a new feature extraction model, generalized perceptual linear prediction (gplp), is developed to calculate a set of perceptually relevant features for digital signal analysis of animal vocalizations. the gplp model is a generalized adaptation of the perceptual linear prediction model, popular in human speech processing, which incorporates perceptual information such as frequency warping and equal loudness normalization into the feature extraction process. since such perceptual information is ava ...200616875249
the role of foraging behaviour in the sexual segregation of the african elephant.elephants (loxodonta africana) exhibit pronounced sexual dimorphism, and in this study we test the prediction that the differences in body size and sociality are significant enough to drive divergent foraging strategies and ultimately sexual segregation. body size influences the foraging behaviour of herbivores through the differential scaling coefficients of metabolism and gut size, with larger bodied individuals being able to tolerate greater quantities of low-quality, fibrous vegetation, whil ...200616927101
endotheliotropic elephant herpesvirus, the first betaherpesvirus with a thymidine kinase gene.endotheliotropic elephant herpesvirus (elephantid herpesvirus 1; elhv-1) is apathogenic for african elephants (loxodonta africana), but causes fatal haemorrhagic disease in asian elephants (elephas maximus). this is thought to occur through transmission from african elephants in places where both species are housed, such as zoological gardens. the virus has caused considerable losses in north american and european zoological gardens and thus severely impedes breeding of the endangered asian elep ...200616963736
the structure of the cushions in the feet of african elephants (loxodonta africana).the uniquely designed limbs of the african elephant, loxodonta africana, support the weight of the largest terrestrial animal. besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morph ...200617118065
african elephants show high levels of interest in the skulls and ivory of their own species.an important area of biology involves investigating the origins in animals of traits that are thought of as uniquely human. one way that humans appear unique is in the importance they attach to the dead bodies of other humans, particularly those of their close kin, and the rituals that they have developed for burying them. in contrast, most animals appear to show only limited interest in the carcasses or associated remains of dead individuals of their own species. african elephants (loxodonta af ...200617148317
the elephants of zoba gash barka, eritrea: part 4. cholelithiasis in a wild african elephant (loxodonta africana).a 4.0-kg cholelith was found within the abdominal cavity of a dead wild african elephant (loxodonta africana) in eritrea. analysis of this cholelith by histochemistry, electron microscopy, electrospray mass spectroscopy, and energy-dispersive x-ray spectroscopy revealed it was composed of bile alcohols but no calcium, bilirubin, or cholesterol. bacteria were also found in the cholelith. similar, but smaller, bile stones have been identified previously in other wild african elephants and an excav ...200517312726
pheochromocytoma in an aged female african elephant (loxodonta africana).a 43 yr-old female african elephant (loxodonta africana) collapsed acutely and died. necropsy revealed an enlarged right adrenal medulla. histologic appearance was typical of pheochromocytoma. special stains and electron microscopy demonstrated chromaffin granules, suggesting that the tumor was derived from catecholamine secreting cells of the adrenal medulla, and may have been functionally secretory. serum levels of both norepinephrine and epinephrine were elevated at time of death, supporting ...200517312735
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