Morbidity and mortality in acute viral hepatitides in a hyperendemic region. The role of viral hepatitis E

Official annual statistical data on morbidity in acute viral hepatitides (AVH), including the number of lethal cases, for 1985-1995 were analyzed. Mortality rates per 100,000 of the population at the period of 11 years were calculated for different age groups, sex and the place of residence. 396 and 99 patients were examined for the presence of serological markers of hepatitides A, B and E, respectively, at the periods of epidemic rises in morbidity and satisfactory epidemic situation. In the course of 11 years AVH caused the death of 22,405 persons. In 1985-1987 the average mortality level (ML) reached 12.3-17.8 per 100,000 of the population (with morbidity being 1,200-1,400 and was essentially higher among the rural population in comparison with the urban population. During these years the highest ML, was registered among children aged 0-2 years (190-50 per 100,000) and, among adults, mainly among women aged 20-29 years (21.4-19.6 per 100,000). During the years when the epidemic of AVH was absent, ML among these groups was essentially lower: 40-20 among children aged 0-2 years and 4-5 among women aged 20-29 years. In 1987 in the Fergana Valley hepatitis E was detected in 72.2% of all examined patients, and in the southern areas of the country in 68.7%. A sharp rise on mortality among women of the productive age at the period of the epidemic rise of AVH morbidity in the endemic region indicated that this epidemic was linked with hepatitis E. High ML among young children may be indicative of a highly unfavorable course of hepatitis E in the group of infants, which had never been registered before. This newly established regularity may be used for the retrospective diagnostics of the outbreak of hepatitis E.     

Infectious disease mortality in the USSR

In recent decades infectious and parasitic diseases (class 1 according to the International Classification of Diseases-9) constitute 2-3% of causes in the total morbidity structures in the USSR. The main causes of death among diseases of class 1 are tuberculosis (37%), acute enteric infections (30%), septicemia (11%), viral hepatitides (11%), meningococcal infection (4%), measles (2%). The main groups are children aged up to 2 years (48% of fatal cases of diseases belonging to class 1). The territorial irregularity of mortality indices has been revealed.     

The principles of pre-epidemic diagnosis in the epidemiological surveillance system for HIV infection

The problem of the general introduction of the principles of the pre-epidemic diagnostics of HIV infection was discussed. These principles should be based on the observation of "model" infections (viral hepatitides B, C, D), multipurpose serological monitoring and sociological methods aimed at obtaining the necessary information. The suggestion that the age and sexual structure of HIV-infected patients would be determined by the route of HIV transmission, prevailing on a given territory, including into infection process adolescents and young women and men was made.     

The epidemiological patterns of hepatitis non-A, non-B

The etiological structure of viral hepatitides in three cities of the Volga region was studied. The proportion of hepatitis non A, non B was established: it varied from 3.6% to 18.1% at different territories and depended on the total morbidity level, on the season, as well as on the age of patients. A suggestion was made concerning the role of the parenteral mechanism of the transfer of hepatitis non A, non B at the territory under study.     

Functional activity of endotoxin binding factors in chronic viral hepatitis B and C

The functional state of cell-mediated and humoral antiendotoxin factors in patients with chronic viral hepatitides B and C has been studied. A decreased content of antibodies to glycolipid of chemotype Re and to Escherichia coli O14 with common enterobacterial antigen was shown to occur in these diseases. In addition, a decreased number of neutrophils, eosinophils and thrombocytes has been noted. The conclusion has been made that patients with chronic hepatitides are not protected from the pathogenic action of endotoxin penetrating from the intestines into the systemic blood stream.     

Helminths of amphibians of the Fergana valley of Uzbekistan

Species diversity and some ecological peculiarities of helminthes parasitizing amphibians in the Fergana Valley of Uzbekistan have been investigated. In 652 examined specimens of amphibians (Bufo viridis--237, Rana ridibunda--415 specimens), have been found 32 helminth species belonging to 26 genera of 12 families.     

Scent marking in a territorial African antelope: I. The maintenance of borders between male oribi

Scent marking is ubiquitous among the dwarf antelope and gazelles of Africa, but its function has been the subject of debate. This study examined preorbital gland scent marking in the oribi, Ourebia ourebi, a territorial African antelope. Several hypotheses for the function of scent marking by territorial antelope were tested with observational data. Of these, the hypotheses that scent marking is driven by intrasexual competition between neighbouring males, and that marks serve as an honest advertisement of a male's ability to defend his territory from rivals, were supported best. Thirty-three territorial male oribi on 23 territories marked most at borders shared with other territorial males, and territorial males marked more often at borders shared with multimale groups than at borders shared with a single male. This suggests that males perceived neighbouring male groups as a greater threat to territory ownership than neighbouring males that defended their territories without the aid of adult subordinates. Marking rate was unrelated to territory size or the number of females on adjacent territories, but males with many male neighbours marked at higher rates than those with fewer male neighbours. These results suggest that the presence of male neighbours has a greater effect on the scent marking behaviour of territorial antelope than has been considered previously. Copyright 1999 The Association for the Study of Animal Behaviour.     

Seasonal Changes of Vocal Rates and Their Relation to Territorial Status in Male Galápagos Sea Lions (Zalophus wollebaeki)

Male vocal displays play an important role in sexual selection through both male–male competition and female choice. While this is supported by numerous studies in birds, much less attention has been paid to the role of such displays in mammals. We investigated the function of vocal displays in a polygynous mammal, the Galápagos sea lion (Zalophus wollebaeki). In our study population a large proportion of mature males are unable to establish a territory, providing the opportunity to compare the vocal behaviour between territorial and non‐territorial males. We examined how seasonal patterns of vocalizations differed between territorial and non‐territorial males and how the number of females present in a territory influenced behaviour of territorial males. We found that territorial males vocalized at higher rates than non‐territorial males, and territorial males vocalized more at the onset than towards the end of territory tenure. During the onset of territory‐tenure vocalizations of territorial males were directed more often towards other males than females. Furthermore, we found that vocalizations of territorial males were not only given in male–male interactions, but were also actively directed towards females. Territorial males vocalized at higher rates when more females were present in their territory. Our results suggest that vocalizations are important in male–male interactions, are relevant in territorial disputes and are used as a proxy for females to assess a male’s quality.     

Male dimorphism, territoriality and mating success in the tropical damselfly, Paraphlebia zoe Selys (Odonata: Megapodagrionidae)

The tropical damselfly Paraphlebia zoe has two male morphs: a black-winged (BW) male which is associated with territorial defense of oviposition sites; and a hyaline-winged (HW) male similar in appearance to females, and, compared to the black morph, less frequently found defending territories. In a wild population of this species, we first assessed the relationship between phenotypic traits [male morph, size and territorial status (being territorial or non-territorial)], their role on mating success, and the degree to which a particular territory may contribute to male mating success. Second, to relate a physiological basis of being territorial we compared both morphs in terms of muscular fat reserves and thoracic muscle, two key traits related to territory defense ability. Males of both morphs defended territories although the BW males were more commonly found doing this. BW males were larger than HW males and size predicted being territorial but only within HW males (territorial males were larger) but not in BW males. Male mating success was related to territorial status (territorial males achieved a higher mating success), but not to morph or size. Furthermore, territory identity also explained mating success with some territories producing more matings than others. The BW morph stored more fat reserves which may explain why this morph was more likely to secure and defend a place than the HW morph. However, the HW morph showed higher relative muscle mass which we have interpreted as a flexible strategy to enable males to defend a territory. These results are distant to what has been found in another male dimorphic damselfly, Mnais pruinosa, where the advantage of the non-territorial morph relies on its longevity to compensate in mating benefits compared to the territorial morph.     

The territorial and age-related characteristics of the distribution of patients with non-A, non-B viral hepatitis infected via the fecal-oral mechanism in foci of elevated viral hepatitis morbidity in the Uzbek SSR

The study of patients from 10 foci of acute viral hepatitides for the presence of HBsAg (in the passive reverse hemagglutination test) and anti-hepatitis A virus IgM (in the radioimmunoassay) has shown high frequency and variability in the spread of hepatitis non-A, non-B, the prevalence of adults aged 20-29 years and children aged 2-4 years among persons involved into the epidemic process and the tendency towards an increase in the proportion of hepatitis non-A, non-B in the total number of cases of viral hepatitides in the republic.     

The epidemiological aspects of viral hepatitides in Estonia]

The etiological structure of viral hepatitides among the adult population of Tallinn and the occurrence of markers of hepatitis B and hepatitis C virus infections in medical workers, addict introducing drugs intravenously and hemodialysis patients were studied. Changes in the etiological structure of viral hepatitides were established: they took the form of a decrease in the level of hepatitis A morbidity and the considerable growth of the role of hepatitides B and C, as well as the newly detected circulation hepatitis D virus. About one-third in the structure of morbidity in viral hepatitides were hepatitis cases without markers of hepatitis A, B or C viruses (non-A, non-B, non-C). The highest rates of hepatitis B virus infection (78.9%) and hepatitis C virus infection (82.5%) were detected among drug addicts. Their level of HBsAg was 8.8%. In the group of medical workers, 25% of the examinees, i.e. every fourth person, had markers of hepatitis B virus, while antibodies to hepatitis C virus were detected in 5% of cases. Among hemodialysis patients these rates were 21.4% and 10.7% respectively.     

Territorial defense, territory size, and population regulation

The carrying capacity of an environment is determined partly by how individuals compete over the available resources. To territorial animals, space is an important resource, leading to conflict over its use. We build a model where the carrying capacity for an organism in a given environment results from the evolution of territorial defense effort and the consequent space use. The same evolutionary process can yield two completely different modes of population regulation. Density dependence arises through expanding and shrinking territories if fecundity is low, breeding success increases gradually with territory size, and/or defense is cheap. By contrast, when fecundity is high, breeding success sharply saturates with territory size, and/or defense is costly, we predict fixed territory sizes and regulation by floaters. These "surplus" individuals form a buffer against population fluctuations. Yet floaters can also harm breeder performance, and by comparing population growth of a territorial population to a nonterritorial (and individually suboptimal) alternative, we can quantify the harmful effect of evolutionary conflict on population performance. Territoriality has often been found to increase population stability, but this may come at a cost of reduced equilibrium densities.     

Ritualized behavior in a territorial limpet

The territorial system of the owl limpet Lottia gigantea Sowerby was found to have ritualized characteristics resulting in much less aggressive physical contact between interacting individuals than has been previously implied. Many limpets showed a marked evasion behavior in response to limpet contact while intruding on another limpet's territory. In addition, a resident limpet when performing an aggressive pushing response, usually only pursued an intruder it had repelled for a short distance rather than to the edge of the resident's territory as previously reported. These behaviors strongly suggest a ritualized territorial system. The push-and-pursue territorial behavior that was previously reported for L. gigantea, is the rare exception to the rule; contact between limpets usually results in the intruder retreating, either immediately or subsequent to the thrusts of the resident, the latter only rarely pursuing.     

Territory quality determines social group composition in Ethiopian wolves Canis simensis

1. We contrast the value of four different models to predict variation in territory size as follows: resource density (the ideal free distribution), population density, group size and intruder pressure (relative resource-holding potential). In the framework of the resource dispersion hypothesis, we test the effect of resource abundance and spatial variation in resource distribution on the age/sex composition of social groups. 2. We explore these drivers of territory size and group size/composition in Ethiopian wolves Canis simensis in the Bale Mountains, Ethiopia, using fine-scale distribution maps of their major prey species based on satellite-derived vegetation maps. 3. The number of adult males is correlated with territory size, while prey density, wolf population density and intruder pressure are not associated with territory size. On average, each additional adult male increases territory size by 1.18 km(2). 4. Prey abundance increases with territory size (average biomass accumulation of 6.5 kg km(-2)), and larger territories provide greater per capita access to prime foraging habitat and prey. 5. The age/sex composition of wolf packs is more closely related to territory quality than territory size. Subordinate adult females are more likely to be present in territories with greater proportions of prime giant molerat Tachyoryctes macrocephalus habitat (i.e. >80% of Web Valley territories and >20% in Sanetti/Morebawa), and more yearlings (aged 12-23 months) occur in territories with greater overall prey biomass. 6. Wolf packs with restricted access to good foraging habitat tend to defend more exclusive territories, having a lower degree of overlap with neighbouring packs. 7. The greater per capita access to prey in large groups suggests a strong evolutionary advantage of collaborative territorial defence in this species, although the relative costs of territorial expansion vs. exclusion depend upon the spatial distribution of resources. We propose a model whereby territory size is determined by the number of adult males, with the presence of subordinate females and yearlings dependent on the quality of habitat, and the abundance and distribution of prey, incorporated within territory boundaries.     

First definitive stegosaur from the Middle Jurassic of Kyrgyzstan

Four articulated posterior dorsal vertebrae from the Middle Jurassic (Callovian) Balabansai Svita at Sarykamyshsai locality in the northern Fergana Valley represent the first record of Stegosauria in Kyrgyzstan. The vertebrae cannot be attributed to any known stegosaurian genus. This is one of the oldest records for the Stegosauria.      

A method for assessing the microflora status of the large intestine using a computer

The qualitative and quantitative composition of the microflora of the large intestine has been studied in 31 healthy adults and in 137 patients with acute viral hepatitides A and B. A set of quantitative tests ensuring the complete characterization of the microbiocenosis under study has been proposed. The results obtained in this investigation have been processed by means of a computer with the use of the principles of numeric taxonomy, thus making it possible to obtain the objective criterion of the state of the microflora of the large intestine, expressed by the similarity index.     

Animal interactions and the emergence of territoriality

Inferring the role of interactions in territorial animals relies upon accurate recordings of the behaviour of neighbouring individuals. Such accurate recordings are rarely available from field studies. As a result, quantification of the interaction mechanisms has often relied upon theoretical approaches, which hitherto have been limited to comparisons of macroscopic population-level predictions from un-tested interaction models. Here we present a quantitative framework that possesses a microscopic testable hypothesis on the mechanism of conspecific avoidance mediated by olfactory signals in the form of scent marks. We find that the key parameters controlling territoriality are two: the average territory size, i.e. the inverse of the population density, and the time span during which animal scent marks remain active. Since permanent monitoring of a territorial border is not possible, scent marks need to function in the temporary absence of the resident. As chemical signals carried by the scent only last a finite amount of time, each animal needs to revisit territorial boundaries frequently and refresh its own scent marks in order to deter possible intruders. The size of the territory an animal can maintain is thus proportional to the time necessary for an animal to move between its own territorial boundaries. By using an agent-based model to take into account the possible spatio-temporal movement trajectories of individual animals, we show that the emerging territories are the result of a form of collective animal movement where, different to shoaling, flocking or herding, interactions are highly heterogeneous in space and time. The applicability of our hypothesis has been tested with a prototypical territorial animal, the red fox (Vulpes vulpes).     

Scent‐marking behavior by subordinate Eurasian beavers

Chemical communication by scent‐marking is widespread among mammals and can serve different purposes, such as territory demarcation, mate attraction and self‐advertisement. In this study, we examined scent‐marking behavior by subordinate Eurasian beavers (Castor fiber) in a population in southeast Norway. We conducted scent experiments in 18 family groups, simulating a territory intruder using experimental scent mounds (ESM). In total, we recorded 196 territorial reactions (destroying and/or overmarking of scent mounds). Subordinates contributed 14% of all territorial reactions and first overmarked 12% of the ESM, and the number of subordinates in the family group did not increase the total number of territorial reactions. This suggests that the contribution by subordinates plays a minor role in territorial defense. The number of territorial reactions by subordinates was positively related to the age of their parents, suggesting that subordinates might take over territorial duties with increasing parental senescence, likely because they have increased chances of inheriting the territory. Increased experience in territorial activities possibly helps subordinates to successfully gain and defend a territory of their own.     

Clinically conditional variants of the immune response in viral hepatitis A and B in children

The immunity characteristics of the T-, B- and A-systems have been studied on the basis of the data registered in the dynamics of the acute period of the disease and several times in catamnesis during 6-12 months of the convalescence period in 217 children with viral hepatitis A and 99 children with viral hepatitis B. The clinical course of viral hepatitis A and that of viral hepatitis B have been found to have certain parallels in their development, as well as specific features of immune response, which can be subdivided into 3 main groups: (a) immunological imbalance, (b) the phase of immunodepression and (c) secondary immunodeficiency. The distinguishing of the variants of immune response and their clinical interpretation are of practical importance for the early prognostication of the course and outcome of the processes and for the differentiated approach to the treatment of viral hepatitides in children.     

Sex difference in the communicatory significance of localized defecation sites in Arabian gazelles (Gazella arabica)

Mammalian scent marking in localized defecation sites (latrines) has often been interpreted in the context of (male) territory defense. However, latrines could have different functions in males and females, especially where territorial males monopolize groups of females with stable social alliances and pronounced home range overlap. We investigated the communicatory significance of latrines in wild Arabian gazelles (Gazella arabica) and assessed the spatial distribution of latrines within home ranges. Latrine density and utilization was highest in the center of female group home ranges, and less frequent in peripheral home range sections, pointing towards communication within groups rather than towards territoriality. When considering male home ranges, latrine densities and utilization were higher in non-overlap zones, contradicting a territorial function. This pattern appears to be caused by more females than territorial males per given area establishing latrines. A subsequent survey of latrine utilization, based on camera trapping, suggests that males use latrines for territory defense: males visited latrines in overlap zones disproportionally more often than females, and successions of two males prevailed. Our study thus highlights that male territorial marking can be masked when males and females use the same marking system for different purposes.