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At least 541 records · Page 30Linked to original sources
PubMed1987

Nut-like oil seeds: food for monkeys, chimpanzees, humans, and probably ape-men.

The hypothetical hyperrobust australopithecine gnathic nutcracker adaptation is reexamined in light of ecobotanical information on edible wild nuts provided by the flora of tropical and subtropical Africa. The nut producing species are tree-forms. Those of the forest region do not as a rule produce fruits with edible mesocarps. In contrast, the woodland savanna species (particularly in the Zambezian region) characteristically provide an important whole fruit, i.e., a nutritious mesocarp in addition to edible oil-rich nut seeds. These fruits drop from the tree before they are fully mature and go through the final ripening phase on the ground. They are important seasonal foods for a variety of vertebrates, including primates, elephants, and antelope. Altogether the nuts exhibit a broad range of toughness values, measured here as strength under compression. The woodland nuts are not as tough (177-934 kg force, breaking load) as those of the tropical forest (192-1,673 kg force). The seed-predators of the woodland species include squirrels, baboons, warthogs, and parrots. Paleoecological analyses indicate that it was the woodland nuts that were probably available to Australopithecus boisei and A. robustus. Preliminary estimates of adult male gnathic nut-cracking capabilities suggest that A. boisei could have orally cracked a significant portion of the woodland nuts. In spite of this, ecobotanical data indicate that we can probably reject the hypothesis that these hominids were year-round gnathic nut-cracking specialists. Both the indirect and direct evidence support this conclusion.

Africa↗
PubMed2005

Sexual dimorphism of vocal control nuclei in budgerigars (Melopsittacus undulatus) revealed with Nissl and NADPH-d staining.

Nissl staining and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry were used to explore the existence of sexual dimorphism in vocal control nuclei of adult budgerigars (Melopsittacus undulatus), a parrot species capable of lifelong vocal learning. Behavioral studies indicate that adult males possess larger vocal repertoires than adult females and learn new calls more quickly. The results of the present study show that the volumes of all vocal nuclei, as measured using both Nissl-stained and NADPH-d-stained material, as well as the total numbers of NADPH-d neurons, were 35-110% greater in males. Furthermore, all vocal nuclei exhibit conspicuous NADPH-d staining compared to surrounding fields in both adult males and females. Nevertheless, there were no significant gender differences in either the intensity of neuropil staining or the densities of NADPH-d neurons in vocal nuclei. Moreover NADPH-d neuron somal shapes were similar in males and females. Diameters of NADPH-d neurons in vocal nuclei were 8.5-32% larger in males than in females. Greater size of NADPH-d neuronal somata in males may be a general property of this cell type in budgerigars because a similar gender difference was found in a visual nucleus, the entopallium, which is not directly associated with the vocal control system and does not exhibit sexual dimorphism in total volume or total NADPH-d neuron numbers. Taken together, the results of the present study favor the hypothesis that superior lifelong vocal learning ability in male budgerigars rests largely on larger volumes of vocal control nuclei in males rather than on sexual dimorphism in the internal composition of vocal nuclei.

Animals↗
PubMed2005

Neuronal activation related to auditory perception in the brain of a non-songbird, the ring dove.

In songbirds, parrots, and hummingbirds, which need to learn their songs, exposure to conspecific song leads to increased expression of the immediate early gene (IEG) ZENK in a number of forebrain regions, including the caudomedial nidopallium (NCM) and the caudomedial mesopallium (CMM). Here we investigated the pattern of IEG expression in response to auditory stimulation in the brain of the ring dove (Streptopelia risoria), a non-songbird that does not need to learn its vocalizations. Ring dove males were exposed to conspecific vocalizations (coos), to heterospecific vocalizations (zebra finch song) or they were kept in silence. IEG expression was investigated by means of immunocytochemical analysis of the distribution of the ZENK protein product Zenk. In all three groups there was Zenk expression in several forebrain regions including the NCM and the CMM, similar to earlier findings in song-learning species. Quantitative analysis of the NCM, the CMM, and the hippocampus revealed significantly greater Zenk expression in birds exposed to conspecific vocalizations than in birds kept in silence, in the CMM only. These results show that there is substantial Zenk expression in the forebrain of a non-song-learning bird, comparable to that in avian song-learning taxa. These findings suggest that there is IEG expression specific to conspecific auditory stimulation in the CMM in both songbirds and non-songbirds.

Acoustic Stimulation↗
PubMed1989

Effects of the organophosphate insecticides diazinon and parathion on bobwhite quail embryos: skeletal defects and acetylcholinesterase activity.

Bobwhite quail eggs were injected at 48 or 72 hr of incubation with various doses of the organophosphate (OP) insecticides diazinon or parathion and the embryos were examined after an additional 48 hr of incubation by both histological and cartilage-staining methods. Bobwhite embryos did not display the notochordal folding or vascular enlargement reported for OP-injected chicken embryos. Cartilage staining of embryos injected with insecticide at 72 hr of incubation and recovered at day 12 of incubation revealed severe shortening and contortion of the vertebral axis, as well as tibiotarsal, rib, and sternum defects. Parathion was more potent in causing skeletal defects than diazinon. No type I defects (micromelia, parrot beak) were detected. Radiometric acetylcholinesterase (AChE) assays of whole embryo homogenates were performed for day 6, 9, and 12 diazinon-injected and control embryos. Diazinon effected drastic reductions in AChE activity. Although the AChE and axial skeletal responses of bobwhite embryos to OP injection are similar to those reported in the literature for other species, some major differences in the bobwhite response were noted: namely, the absence of notochordal folding in the young bobwhite embryo and the absence of type I defects at day 12. These differences suggest that further studies with the bobwhite quail would be useful in clarifying the mechanisms involved in OP-induced teratogenesis.

Acetylcholinesterase↗
PubMed1989

Anatomy of the avian cecum.

The gross anatomy of the avian ceca is reviewed. In most birds, right and left ceca arise laterally or ventrolaterally at the junction of the small and large intestines. In a few species, the ceca open into the rectum ventrally or dorsally. In many herons and bitterns, only one cecum is present, and in the secretary bird there are two pairs of ceca. Ceca are absent in woodpeckers, hummingbirds, swifts, kingfishers, pigeons, mousebirds, cuckoos, and parrots. Ceca may be classified according to length into long, moderately or poorly developed, and vestigial types. In most birds, the ceca are simple tubular structures with minor variations in shape. However, in a few species, including the ostrich, rheas, kiwis, some tinamous, the red-throated loon, screamers, the satyr tragopan, the great bustard, and the pin-tailed sandgrouse, the ceca are sacculated or have diverticula. There is usually no correlation between the development of the ceca and systematic position. Except in grouse (Tetraonidae), in which the long ceca are related to the fibre content of the diet, the correlation between cecal development and diet is extremely limited. There is no relationship between the size of the ceca and the length and width of the rectum.

Animals↗
PubMed1995

Windows on animal minds.

The simple kinds of conscious thinking that probably occur in nonhuman animals can be studied objectively by utilizing the same basic procedure that we use every day to infer what our human companions think and feel. This is to base such inferences on communicative behavior, broadly defined to include human language, nonverbal communication, and semantic communication in apes, dolphins, parrots, and honeybees. It seems likely that animals often experience something similar to the messages they communicate. Although this figurative window on other minds is obviously imperfect, it is already contributing significantly to our growing understanding and appreciation of animal mentality.

Animal Communication↗
PubMed1992

Expression of the carbohydrate epitope 3-fucosyl-N-acetyl-lactosamine (CD15) in the vertebrate cerebellar cortex.

The distribution of the carbohydrate epitope CD15 was investigated on paraffin sections of the brains of man and mammals (monkey, dog, rabbit, rat, mouse, dolphin), reptile, bird and fish by means of immunohistochemistry. This paper demonstrates a differential expression of the CD15 epitope in the cerebella of these various vertebrates. CD15 positivity was found on glial cells and neuronal structures. In adult brains two major distribution patterns were distinguished: one with very intense labelling of the molecular layer, for which the rat is representative, the other with very low immunoreactivity in this layer (mouse). Amongst the rodents (mouse, rat and rabbit), as well as the monkey and human, the positivity in the molecular layer could be attributed to Bergmann fibres of the Golgi epithelial cells. A typical parasagittal band pattern, present in the mouse molecular layer for CD15, which is absent in rat and rabbit molecular layer, is present during human cerebellar development. CD15 positivity on neuronal structures is found on parallel fibres in the developing human, on the lower stellate cells in the dog, and in climbing fibres of the dolphin and, presumably, the catfish too. Moreover, within the parrot cerebellum, large CD15-positive mossy fibre-like endings are found just at the infraplexiform layer.

Adolescent↗
PubMed1995

Isolation of Cryptococcus neoformans var. neoformans from bird droppings, fruits and vegetables in Mexico City.

The presence of Cryptococcus neoformans in various natural sources, such as bird droppings, fruits and vegetables, was investigated. A total of 711 samples were analyzed; C. neoformans var. neoformans was isolated from seven out of 74 bird droppings (9.5%), with parrots as one of the most significant sources. Fruits were positive in 9.5% of the 169 samples studied, specially citrus fruits, particularly grapefruit, in which the highest frequency was found. From the 468 vegetable samples, only 20 were positive (4.2%). It is emphasized that five of the positive vegetables species are autochthonous to Mexico: avocado (Nectandra salicifolia), beet (Beta vulgaris var. quinopodiace), chayote (Sechium edule), stringbean (Cassia sp), and nopal (Opuntia ficus-indica).

Animals↗
PubMed1991

"Why do (don't) you ask?" Transference and the desire (not) to know.

One of the criterial distinctions of psychoanalysis is its renunciation of indoctrination through suggestion. In spite of the fact that psychoanalysis is both an organized body of knowledge and a disciplined form of interpersonal influence, it regards an analyst who tells the analysand what to think or do as essentially doing harm by substituting a new form of prejudice and alienation for the preexisting form he is attacking. Even though an analyst regards his knowledge of psychoanalytic theory as adequate at a general level, this "truth" is not an adequate mode of discourse with an individual. Why not? It is a fact that analysands often do not accept an analyst's idea. However, the fundamental problematic of clinical psychoanalysis comes precisely at the point that the analysand would accept the analyst's idea, involving the distinction between a properly psychoanalytic cure and a transference cure. Psychoanalytic theory itself holds that unreflective incorporation of another's idea about oneself comes at the expense of autonomous and spontaneous self-revelation. Despite its resolute pursuit of new truths, the aim of psychoanalysis is less concerned with attaining specific ideas about unrecognized conflicts than it is with achieving a general attitude--that self-understanding requires a capacity to admit dubious and unwanted ideas and feelings that symptoms, dreams, and free associations bring to light. This "psychoanalytic" attitude permits a new type of discourse in which the person recognizes himself or herself through expression, rather than parrotting the analyst's (or others') words, or continuing rigidly to hide the truth of desire for oneself. In the long run, psychoanalysis offers to correct a primary misunderstanding: that one can acquire a comprehensively true image of oneself. As Barratt (1988) emphasizes, this transformation is tantamount to a change in personal epistemology for the analysand and a change in epistemological theory for the culture as a whole. In our culture, most analysts and lay people alike take for granted that the ego is an agent that is to be integrated and strengthened in order to direct one's life. Likewise, the unconscious is commonly regarded as a type of savage alter ego that must be mastered by the ego. According to Lacan's critique, the ego is a snare and a delusion for the patient, however highly commended by society it may be, because its very essence is to furnish the illusion of enduring self-knowledge.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1980

Isolation and serological differentiation of a herpesvirus from bobwhite quail (Colinus virginianus, L. 1758).

An infectious agent was isolated from the liver of bobwhite quails (Colinus virginianus, L. 1758). The agent was sensitive to chloroform and its multiplication was inhibited by 5-iodine-2-deoxy-uridine. It passed filters with a pore diameter of 220 nm and more but not 100 nm filters. Electron microscopic examination revealed numerous nucleocapsids with hollow capsomeres and few enveloped particles in the supernatant fluids of infected cultures. The nucleocapsids were calculated to have 162 capsomeres on their surface. Using the plaque reduction method for neutralization tests no serological cross reactions could be detected between the quail isolate and sera against Marek's disease virus, turkey herpes-virus (HV), duck enteritis HV, infectious laryngotracheitis HV, amazon parrot HV, great horned owl HV, eagle owl HV, snowy owl HV, falcon HV, pigeon HV, Lake Victoria Cormorant HV, and stork HV. The isolate from bobwhite quail did only cross-react with antiserum against crane HV. It is concluded that the isolated virus is a member of the avian herpesvirus group and it is proposed to tentatively term it herpesvirus colinum (from Colinus virginianus = bobwhite quail).

Animals↗
PubMed1990

The future of DNA-DNA hybridization studies.

This article draws on many vertebrate examples to assess the future of DNA-DNA hybridization studies. I first discuss whether applications of the method have reached the point of diminishing returns, or rather the start of a great leap forward, in our evolutionary understanding. Vertebrate groups whose relationships are especially likely to be illuminated include parrots, pigeons, bats, pinnipeds, mammalian carnivores, frogs, and rodents. There are at least two reasons why classifications based on DNA-DNA hybridization may prove to differ from classifications based on particular character, whether these be noncoding DNA sequences or protein sequences or anatomical characters. Because evolutionary relationships can now be deduced independently of anatomical characters, this should permit a renaissance in comparative anatomical studies of adaptation. The origin of major functional shifts from changes in a small fraction of the genome is illustrated by polar bears, sea otters, warblers, vultures, and especially by humans.

Animals↗
PubMed2002

Mapping vocal communication pathways in birds with inducible gene expression.

Expression mapping of activity-dependent genes has been very useful to reveal brain activation patterns associated with specific stimuli or behavioral contexts. In addition, activity-induced neuronal gene expression is likely associated with neuronal plasticity and may be part of the mechanism(s) involved in long-term memory formation. Analysis of the immediate-early gene zenk has been used to generate high-resolution maps of brain activation associated with perceptual and motor aspects of vocal communication in songbirds and other avian groups. This molecular approach has generated novel insights into the organization of perceptual and motor control pathways for vocal communication in birds. Its impact on the neurobiology of birdsong will be reviewed here. Emphasis will be given to the caudomedial neostriatum, the area that shows the most robust zenk induction upon presentation of song to songbirds. Another focal point will be the comparative analysis of vocally induced zenk expression patterns across the avian orders that evolved vocal learning (i.e., songbirds, parrots, and hummingbirds). New research directions indicated by this molecular analysis will be discussed throughout.

Animal Communication↗
PubMed2006

Auditory feedback is necessary for long-term maintenance of high-frequency sound syllables in the song of adult male budgerigars (Melopsittacus undulatus).

Among avian species that communicate using vocalization, songbirds (oscine Passeriformes), hummingbirds (Trochiliformes), and parrots (Psittaciformes) are vocal learners. Early studies showed that songbirds require auditory feedback for song development in young and maintenance in adults. To determine whether auditory feedback is also necessary for adult song maintenance in non-passerine species, we deprived adult male budgerigars (Psittaciformes) of auditory input by surgical cochlear removal. Songs of the deafened birds changed within 6 months after auditory deprivation. In postoperative songs, high narrowband syllables, which comprised frequency-modulated narrowband elements with relatively high fundamental frequencies of 2-4 kHz, decreased significantly. High harmonic broadband syllables, with fundamental frequencies >/=2 kHz, also decreased. The altered proportions of syllables were subsequently retained, and maintained 12 months after deafening. The sequence linearity score, a parameter representing the stereotypy of the syllable sequence, was higher than that before deafening. The inter-syllable silence was prolonged. Little change was observed in the songs of intact and sham-operated birds. The significant decrease in high-frequency syllables and song alteration followed by stabilization resembled the results with songbirds, although song stabilization took a long time in budgerigars. Therefore, our results suggest that psittacine budgerigars and oscine songbirds require auditory feedback similarly for adult song maintenance.

Acoustic Stimulation↗
PubMed2006

History of experimental psychology from an Estonian perspective.

A short review of the development of experimental psychology from an Estonian perspective is presented. The first rector after the reopening of the University of Dorpat (Tartu) in 1802, Georg Friedrich Parrot (1767-1852) was interested in optical phenomena which he attempted to explain by introducing the concept of unconscious inferences, anticipating a similar theory proposed by Herman von Helmholtz 20 years later. One of the next rectors, Alfred Wilhelm Volkmann (1800-1878) was regarded by Edwin Boring as one of the founding fathers of the experimental psychology. Georg Wilhelm Struve (1793-1864) played an essential part in solving the problem of personal equations. Arthur Joachim von Oettingen (1836-1920) developed a theory of music harmony, which stimulated his student Wilhelm Friedrich Ostwald (1853-1932) to study colour harmony. Emil Kraepelin (1856-1926), the founder of modern psychiatry, is by far the most important experimental psychologist who has worked in Estonia. His successor Wladimir von Tchisch (1855-1922), another student of Wilhelm Wundt, continued Kraepelin's work in experimental psychology. The lives of Wolfgang Köhler (1887-1967), who was born in Reval (Tallinn), and Oswald Külpe (1862-1915), who graduated from the University of Dorpat, extended the link between the history of experimental psychology and Estonia. Karl Gustav Girgensohn (1875-1925), the founder of the Dorpat School of the psychology of religion, stretched the use of experimental methods to the study of religious experience.

Congresses as Topic↗
PubMed2005

Nocturnal activity of phlebotomine sandflies (Diptera: Psychodidae) in a cutaneous leishmaniasis focus in Chichaoua, Morocco.

The nocturnal activity of phlebotomine sandflies (Diptera: Psychodidae) was studied "at an epidemic focus" on human cutaneous leishmaniasis due to Leishmania tropica Wright in Chichaoua province, in Morocco. Sandflies were collected using light and sticky-paper traps changed at 2-h intervals, inside and around houses, in August and October 2004. Overall, 633 sandflies, belonging to six species of Phlebotomus and three of Sergentomyia, were collected. Sandfly activity was nocturnal and higher at twilight. Several activity patterns were observed according to the species. Phlebotomus (Paraphlebotomus) sergenti Parrot, 1917, the suspected vector of L. tropica in this focus, was caught during each collection performed from 1900 to 0500 hours, the numbers of species caught peaked at 1900-2100 hours. There were seasonal variations of the nocturnal activity, which could be related to the variations in temperature and relative humidity.

Animals↗
PubMed2003

New evidence of animal consciousness.

This paper reviews evidence that increases the probability that many animals experience at least simple levels of consciousness. First, the search for neural correlates of consciousness has not found any consciousness-producing structure or process that is limited to human brains. Second, appropriate responses to novel challenges for which the animal has not been prepared by genetic programming or previous experience provide suggestive evidence of animal consciousness because such versatility is most effectively organized by conscious thinking. For example, certain types of classical conditioning require awareness of the learned contingency in human subjects, suggesting comparable awareness in similarly conditioned animals. Other significant examples of versatile behavior suggestive of conscious thinking are scrub jays that exhibit all the objective attributes of episodic memory, evidence that monkeys sometimes know what they know, creative tool-making by crows, and recent interpretation of goal-directed behavior of rats as requiring simple nonreflexive consciousness. Third, animal communication often reports subjective experiences. Apes have demonstrated increased ability to use gestures or keyboard symbols to make requests and answer questions; and parrots have refined their ability to use the imitation of human words to ask for things they want and answer moderately complex questions. New data have demonstrated increased flexibility in the gestural communication of swarming honey bees that leads to vitally important group decisions as to which cavity a swarm should select as its new home. Although no single piece of evidence provides absolute proof of consciousness, this accumulation of strongly suggestive evidence increases significantly the likelihood that some animals experience at least simple conscious thoughts and feelings. The next challenge for cognitive ethologists is to investigate for particular animals the content of their awareness and what life is actually like, for them.

Animal Communication↗
PubMed2005

A new species of Pterothominx Freitas, 1959 (Nematoda: Capillariidae) parasitising psittacine birds (Psittaciformes).

A new species, Pterothominx (Pterothominx) moraveci n. sp. (Trichinelloidea: Capillariidae) is described from an Australian parrot, Barnardius zonarius Shaw (Psittacidae: Psittaciformes), imported from Germany and kept in captivity in the Czech Republic. Males of the new taxon differ from all other species of the subgenus Pterothominx Freitas, 1959, which mainly parasitise galliform birds, in having a shorter spicule (0.925-1.338; mean 1.050 mm), a shorter body length and a different form of armed spicular sheath and bursa. Females differ in having the smallest eggs (40-50 x 20-25; mean 48 x 23 microm) and in other morphometrical characters. From the species P. (P.) totani (Linstow, 1875), which parasitises charadriiform birds, the new species differs in its smaller number of stichocytes (females 42-46, mean 44; versus 50-54), different form of the bursa and praebursal alae, and other characters. This is the only species of Pterothominx that parasitises psittacine birds.

Animals↗
PubMed1985

Effects of diazinon on nucleotide and amino acid contents of chick embryos. Teratogenic considerations.

The effects of diazinon (DZN), an organophosphorus (OP) insecticide, and nicotinamide (Nam) on the pyridine nucleotide, purine and pyrimidine ribonucleotides, and free alpha amino acid contents of chick embryos were determined. The teratogen (DZN) and/or the anti-teratogen (Nam) were administered by the intravitelline route to chicken eggs at day 3 of incubation, and nucleotide and amino acid analyses were made on acid-soluble extracts of homogenates of the embryos at day 10. The results show that the amounts of both the oxidized and reduced forms of NAD and NADP were decreased by the insecticide and restored by Nam. The amounts of the purine and pyrimidine ribonucleotides in the embryos were also decreased by DZN but their changes were proportionately not as great as those of the pyridine nucleotides. The levels of the purine and pyrimidine ribonucleotides were also wholly or partially restored by Nam. Neither DZN nor Nam had any effect on the "energy charge" of the embryos. The levels of free tryptophan (TRP) and histidine (HIS) were decreased by DZN while the levels of threonine (THR) and aspartic acid (ASP) were increased. All other amino acid levels remained virtually unchanged in response to DZN or Nam. Based upon these findings, a possible involvement of TRP in OP insecticide-induced micromelia, parrot beak, and abnormal feathering in chick embryos is considered.

Abnormalities, Drug-Induced↗