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At least 19 recordsLinked to original sources
PubMed1977

[Arteries of the thalamus in man. Choroidal arteries. III. Absence of the constituted thalamic territory of the anterior choroidal artery. IV. Arteries and thalamic territories of the choroidal and postero-median thalamic arterial system. V. Arteries and thalamic territories of the choroidal and postero-lateral thalamic arterial system].

The anterior chor oideal artery cannot be considered as an arterial source for thalamic vascularization. Its territory is primarily pallidocapsular and reaches the thalamus only irregularly and superfically. 2. The posteromedian choroideal and thalamic system, in its infrathalamic portion, gives off lateral mesencephalosubthalamic, inferocentral (for the tips of the arcuate nucleus and the inferolateral part of the centre median nucleus), brachiopulvinarian and posterocentral arteries. In its suprathalamic portion it gives off medial pulvinarian and superomedian thalamic arteries. These arteries irriguate the major part of nucleus medialis and the nucleus anterior. 3. The posterolateral choroideal and thalamic system gives off lateral genicular arteries (for the lateral geniculate body), inferolateral pulvinarian and superolateral thalamic arteries. These arteries irriguate the dorsal part of the interal region of the thalamus.

Arteries↗
PubMed1975

Uganda kob (Adenota kob thomasi): territoriality and the spatial distributions of sexual and agonistic behaviors at a territorial ground).

Possible functions of territorial behavior were evaluated on the basis of observations of agonistic and reproductive activities of Uganda kob at a "territorial ground" (TG) in southwestern Uganda. We have found that male residents of a TG tend to occupy exclusive areas, and that agonistic interactions are concentrated along the boundaries separating adjacent occupied areas. Thus, we conclude that male kob do engage in the active defense of spatially exclusive territories at a TG.

Aggression↗
PubMedDate not supplied

[The epidemic manifestation of natural foci of tick-borne encephalitis on the territory of the Maritime Territory. 2. The spatial differences in the seasonality of tick-borne encephalitis].

Using computer maps of the epidemic process season variations, tick-borne morbidity and lethality in the areas of the Maritime Territory [correction of Primorsky Region] have been analysed. According to season variations of the epidemic process the territory of Sikhote Alin has been divided into two separate parts--northern and southern, with morbidity peak in June and July, respectively.

Disease Outbreaks↗
PubMed1990

The epidemiology of invasive Haemophilus influenzae infections in children under five years of age in the Northern Territory: a three-year study.

A survey of all episodes of invasive Haemophilus influenzae infections that were diagnosed over a three-year period in children seen at the regional hospitals of the Northern Territory has found a significantly (P less than 0.001) higher incidence in children in Central Australia (the Alice Springs and Barkly regions, and the Anangu Pitjantjatjara Lands) than in the Top End (the Darwin, East Arnhem and Katherine regions), and a greater incidence in Aboriginal than in non-Aboriginal children. Identified risk factors for Aboriginal children were infancy (more than 70% of cases occurred before 12 months of age), sex (with a predominance in girls) and residence in Central Australia; the estimated annual incidence for Central Australian Aboriginal children was 991 cases per 100,000 children. There was a significant correlation (r = 0.62) between the total number of cases diagnosed each month in Central Australia and the mean monthly temperatures recorded in Alice Springs. Whereas virtually all cases of invasive H. influenzae infection in non-Aboriginal children were caused by type b strains, strains other than type b caused 15% of the cases in Aboriginal children. The possibilities for prevention by immunization are discussed.

Age Factors↗
PubMed1989

Hormonal correlates of migration and territorial behavior in juvenile willow tits during autumn.

This study compared plasma levels of dihydrotestosterone, testosterone, corticosterone, luteinizing hormone, growth hormone, and prolactin in migrating juvenile willow tits with those in territorial juveniles. Both categories of birds were caught in late September. Migrating juveniles had higher plasma levels of corticosterone than territorial juveniles. Only corticosterone secretion was affected by "handling stress" in both migrating and territorial juveniles. However, territorial birds showed a much stronger relationship between these two variables. It is suggested that high corticosterone levels are involved in the emigration of juveniles out of the coniferous forest. Only juveniles were found among the migrating willow tits, and these birds were not well adapted for migration. Migrating juvenile males had less fat stored than did territorial ones. Furthermore, migrating juvenile males had higher liver/somatic index and higher plasma levels of growth hormone than did territorial males. These results indicate that migrating males had been, or were, exposed to food restrictions. The same proportion of migrating and territorial juveniles, males as well as females, had high plasma levels of testosterone. We suggest that these high levels were caused by recent aggressive interactions. To test the hypothesis that high plasma levels of testosterone are important for a juvenile to become a member of a territorial winter group, we performed a field experiment in which juveniles were given testosterone implants (controls were given empty silastic tubes) at the beginning of the territorial establishment period. The same proportion of testosterone-implanted birds and control birds succeeded in becoming members of territorial winter groups. Thus, testosterone does not seem to play an essential role in autumn territoriality, and it does not prevent autumn migration.

Animals↗
PubMed1985

The territorial defense hypothesis and the ecology of insular vertebrates.

Insular lizards, birds, and mammals in high-density populations often exhibit reduced situation-specific aggression toward conspecifics. This aggressive behavior can be expressed in the form of (1) reduced territory sizes, (2) increased territory overlap with neighbors, (3) acceptance of subordinates on the territory, (4) reduced aggressiveness to certain classes of conspecifics, or (5) abandonment of territorial defense. These behavioral traits can be explained by two nonexclusive hypotheses. The resource hypothesis suggests that territorial behavior is primarily adjusted to resource densities, and that resources are more abundant on islands than on the mainland (e.g., because of a lack of competing species). The defense hypothesis suggests that, in addition to any effects of resources, the costs of defense against both territorial intruders and contenders for vacant territories are higher on islands. Recent theoretical and empirical studies indicate that these behavioral changes can occur as a result of elevated defense costs, independent of resource densities. Reduced predation, more benign climates, and an absence of habitat sinks on islands would all tend to increase the density of potential intruders and contenders, and hence the costs of defense for owners of insular territories. The two hypotheses differ in their predictions about the rates of biomass production (growth or reproduction) for holders of insular territories. Reproductive and growth data from insular-mainland pairs indicate the importance of elevated defense costs, and also suggest that many insular vertebrates reallocate their breeding resources so as to produce young that are more competitive. The suite of ecological and behavioral traits exhibited by insular territorial vertebrates can best be explained by three factors operating in concert: higher available resource densities, higher defense costs, and (sometimes) a reallocation of resources to produce young that are more competitive.

Animals↗
PubMed1990

Cerebellar infarction in the territory of the anterior and inferior cerebellar artery. A clinicopathological study of 20 cases.

Clinicopathological reports on infarction in the territory of the anterior inferior cerebellar artery (AICA) are rare. In the present series cerebellar infarcts involved only the AICA territory in 13 cases. They were bilateral in 3 cases. In these pontocerebellar infarcts the middle cerebellar peduncle was the core of the affected territory. It was seldom selectively affected. In a few cases, the infarction extended to the flocculus. Next most frequently involved was a thin band of tissue in the adjacent cerebellar white matter, comprising laterally the neighbouring cerebellar lobules. The largest infarcts extended to the anterior and inferior aspects of the cerebellum. In these cases, the posterior inferior cerebellar artery (PICA) was hypoplastic. In most infarcts, the inferolateral pontine territory was involved, the infarction sometimes extending up to the middle third of the lateral pons and down to the superior part of the lateral medulla. No brainstem compression or tonsillar herniation were observed with infarcts affecting the AICA territory alone. Clinically, involvement of several cranial nerves (facial palsy, multimodal trigeminal sensory impairment, deafness, sometimes with tinnitus, a vestibular syndrome, or lateral gaze palsy) was constant. Cerebellar signs and motor weakness occurred frequently. Contralateral pain and temperature sensory loss was present at times. Horner's syndrome or skew deviation was rare. Study of the arteries showed that arterial occlusion was mainly due to thrombosis superimposed on atheromatous stenosis. In 7 cases, the infarction also involved the PICA territory or the PICA and the superior cerebellar artery territories. These extensive infarcts were often associated with tonsillar herniation and massive paramedian brainstem infarction. The cases in which the territories of the three cerebellar arteries were affected presented in deep coma, together with tetraplegia in some patients. Those in which PICA and AICA territories were involved together presented with similar clinical features as in the cases in which only the AICA territory was involved.

Aged↗
PubMed1989

Geographic variation in the territorial success of Drosophila melanogaster males.

Drosophila melanogaster males defend food against other males to increase their access to females on food. The territorial behavior of stocks collected from Townsville, Corindi, and Melbourne on the east coast of Australia were compared. Males from these stocks showed the same incidence of territorial encounters. However, Melbourne males were more successful at obtaining territories in competition with Townsville or Corindi males. This difference could be accounted for largely by variation in body weight, although territorial success was also determined by other factors because Townsville and Corindi males that held territories were not heavier than Melbourne males. In reciprocal crosses between the populations there was directional dominance for increased territorial success. F1 males were of intermediate weight and F1 males that held territories tended to be lighter than territorial Melbourne males. Melbourne males were more successful than Townsville males because they tended to win escalated encounters, resulting in displacement of territory residents.

Animals↗
PubMed1987

Effects of testosterone manipulations on nonbreeding season territorial aggression in free-living male lizards, Sceloporus jarrovi.

Seasonal changes in testosterone levels in male mountain spiny lizards (Sceloporus jarrovi) are correlated tightly with seasonal changes in intensity of aggressive territorial defense. Testosterone levels are lowest in the winter when males aggregate, are moderately elevated during the summer when males show low-intensity territorial defense, and are highest during the fall breeding season when males show high-intensity territorial defense. In this study, we tested the hypothesis that changes in testosterone levels cause these seasonal changes in territorial behavior. We experimentally increased and decreased circulating testosterone levels in free-living males during the summer, when they display non-breeding season territoriality. Artificially increasing testosterone levels to levels equivalent to the breeding season significantly increased some, but not all, measures of territorial aggression. Levels of aggression attained, however, were still well below those typical of breeding season males. This implies that the transition to full breeding season levels of aggression is caused only partly by an increase in testosterone levels. Castration of males during the summer had no effect on several measures of territorial aggression. Thus the activation of nonbreeding season territoriality, which precedes testicular recrudescence by several months, is relatively unaffected by testosterone levels. Taken together these results suggest that the same behavior, in this case territorial aggression, may be controlled by different mechanisms in different seasons.

Aggression↗
PubMed1985

Short-term changes in plasma levels of hormones during establishment and defense of a breeding territory in male song sparrows, Melospiza melodia.

When territorial male song sparrows are captured and removed from their territories, previously unmated and nonterritorial males will take over those vacant territories within 12-72 hr. Plasma levels of testosterone are elevated in these replacement males as well as in their neighbors. Since the latter already have territories, it is suggested that the agonistic interactions over territory boundaries, or behavioral stimuli from challenging males, rather than ownership of a territory per se, stimulates secretion of testosterone. To test this hypothesis further, male song sparrows were challenged by experimental simulation of a territorial intrusion. This procedure involved placing a caged male song sparrow in the center of the subject's territory and playing tape recorded conspecific song through an adjacent speaker. Responding males were then captured at intervals after onset of the intrusion. Plasma levels of testosterone were significantly higher in males exposed to experimental territorial intrusion than they were in controls, supporting the hypothesis that behavioral stimuli emanating from an intruding male can act as supplementary information stimulating secretion of testosterone.

Aggression↗
PubMed1990

Autumnal territorial aggression is independent of plasma testosterone in mockingbirds.

Mockingbirds (Mimus polyglottos) show intense territorial activity in the autumn as newcomers attempt to establish space within resident populations. Examination of autumnal territorial behavior showed that unmated males sing more and engage in more territorial fights than mated males. Newcomers that have just acquired space also sing more and show more territorial fights than birds resident to the population for at least one prior season. Among established residents, the average number of territorial fights was greater in birds that shared more territory boundaries with new residents. Radioimmunoassay of plasma samples taken from males during the molt and following the onset of territorial defense showed that during both periods plasma concentrations of testosterone (T), dihydrotestosterone (DHT), and estradiol were basal or below the sensitivity of the assay system. Moreover, groups of males that differed in song and territorial aggression did not differ in plasma concentrations of T, DHT, or luteinizing hormone (LH). Hormone analyses confirm measurements on several other avian species suggesting that sex steroid concentrations are low in the fall and winter and that variations in aggressive behavior at this time of year may be unrelated to LH and androgen levels. Our observations contribute to a growing body of work in temperate passerines indicating that the role of androgens in mediating aggressive challenge may be restricted to the breeding season. The possible hormonal basis (if any) of song and territorial aggression in mockingbirds outside the breeding season remains obscure.

Aggression↗
PubMed1988

The venous territories of muscles: anatomical study and clinical implications.

The venous architecture of the muscles of the body was studied in 425 specimens obtained from four fresh cadavers after total body injection with a radio-opaque lead oxide mixture. In 40 muscles the site and orientation of the valves was identified with the operating microscope. The venous network of each muscle was compared with similar arterial studies. The venous territories in each muscle matched the arterial territories. Where arterial territories were linked with choke arteries the venous territories were linked by veins devoid of valves which allowed bidirectional flow--the "oscillating veins". Elsewhere the valves of adjacent territories were directed away from each other and towards their respective pedicles. These anatomical observations reinforce our angiosome concept. The muscles were classified into Type A, B and C where there were one, two or more territories respectively. When a skin paddle is designed distally on a Type B or C muscle its venous return at first must negotiate the anatomical obstruction of the valves of the distal muscle territory before reaching the safety of the oscillating veins and the venous territory of the drainage pedicle. Finally, afferent veins were noted entering many muscles from the superficial and deep tissues. This highlights the importance of the muscles in aiding venous return by their muscle pump action.

Arteries↗
PubMedDate not supplied

The vascular territories in the cerebellum and brainstem: CT and MR study.

More than 100 CT and 15 MR studies of infarcts in the cerebellum and brainstem were reviewed to define the most typical distribution of infarcts in the different vascular territories. Posterior inferior cerebellar artery and anterior inferior cerebellar artery territories are variable in size and are in a sort of equilibrium with each other. The posterior inferior cerebellar artery territory in transverse sections reveals a characteristic posterior crescent caused by its cranial posterior extension. The anterior inferior cerebellar artery territory may be limited to the lateral inferior pontine and floccular regions but usually extends over the whole petrosal surface of the cerebellum up to the lateral angle. Superior cerebellar artery territory is the most extensive territory and includes the largest part of the deep white matter. Infarcts in a single-branch distribution, vermian or hemispheric, have a characteristic sagittal or oblique orientation. Watershed cerebellar infarcts can also be recognized. In the brainstem, paramedian, lateral, and dorsal penetrating arteries have characteristic distributions at the medullary, pontine, and mesencephalic levels. With MR, lateral medullary infarcts can be demonstrated. Paramedian penetrating arteries are paired, and symmetric and small infarcts at medullary and pontine levels are sharply delimited on the midline. At the mesencephalic level, infarcts in this distribution usually involve all the arteries originating from the tip of the basilar artery and from the precommunicating segment of the posterior cerebral arteries, resulting in a central mesencephalic infarct with bilateral upward extension in the thalami. The different vascular territories in the cerebellum and in the brainstem are illustrated in schematic drawings in transverse, coronal, and sagittal planes. Knowledge of the vascular territories gained by the multiplanar capabilities of MR, and knowledge of the CT patterns of enhancement and evolution, will improve recognition and definition of infarcts.

Brain Stem↗
PubMed1991

Territorial aggression and song of male European robins (Erithacus rubecula) in autumn and spring: effects of antiandrogen treatment.

Male robins aggressively defending a feeding territory in winter have low levels of testosterone, while males defending a breeding territory in spring have elevated levels of testosterone. Song is an integrated part of territorial defense during both phases. We investigated whether testosterone is involved in the expression of these behaviors by treating free-living and captive male robins during both phases with the antiandrogen flutamide. Results suggest that, similar to species in which territoriality is restricted to the reproductive phase, aggressive defense of a breeding territory by male robins is facilitated by androgens. Territorial defense during the nonbreeding season, however, does not require androgenic activity. Singing frequency, on the other hand, was not significantly reduced during either phase by flutamide application. Since the quality of male song changes with season we suggest that the incorporation of sexual signals into male song during breeding depends on testosterone, but that the year-round production of territorial "keep out" signals is independent of testosterone.

Aggression↗