Different Levels Of Aggressiveness Research Articles

Agonistic Behavior Between Individual Worker Termites from Three Cuticular Hydrocarbon Phenotypes of <I>Reticulitermes</I> (Isoptera: Rhinotermitidae) from Northern California

Bioassays examining aggression in termites have typically been performed by pairing groups of workers from different colonies. We examined whether similar results would be observed using bioassays with individual workers. We report the results of pairings of individual workers of Reticulitermes spp. of three different hydrocarbon phenotypes (CA-A, CA-B, and CA-C). Resulting agonistic behavior between individuals can be used to infer relatedness of workers from different foraging groups because identification of species of Reticulitermes is often difficult. Pairings consisted of two termites from the same colony or from different colonies with the same or different phenotypes. We recorded avoidance behavior and immediate aggression during 5-min observations and mortality at 24 h. Intercolonial/intraphenotype pairings paralleled group bioassays with low levels of immediate aggression; however, individual pairings had lower levels of mortality at 24 h. Bioassays using individual Reticulitermes spp. workers in interphenotype pairings yielded results comparable with previously reported group bioassays and could be used in lieu of group bioassays. However, if immediate aggression is lacking, it would be advisable to use group bioassays or increase the number of replications to differentiate intracolonial and intercolonial pairings. Survival rates were the same for all phenotypes when paired with either of the other two phenotypes. There were, however, significant differences in the number of avoidance responses; pairings with CA-C had the highest number of avoidance responses followed by pairings with CA-B and CA-A. There were significant differences in immediate aggression; CA-C was the most aggressive, followed by CA-B and CA-A. Different levels of aggression among phenotypes provide additional evidence that these phenotypes represent distinct taxa or species.

Spatial learning in male mice with different levels of aggressiveness: effects of housing conditions and nicotine administration

The main aim of the present investigation was to evaluate the possible modulation of spatial learning ability by housing conditions and level of aggressiveness in mice, also testing whether differences in locomotion and anxiety could influence this relationship. Additionally, we have examined effects of nicotine in the acquisition and retention of a spatial learning task in groups of mice differing in these variables. NMRI male mice were either group-housed or individually housed for 30 days and then classified into mice with short (SAL) and long (LAL) attack latency after a pre-screening agonistic encounter. Locomotor activity and baseline levels of anxiety of these groups were evaluated in the actimeter and elevated plus-maze. Results indicated that SAL and LAL individually housed mice displayed higher locomotion activity than LAL group-housed mice. In the plus-maze test, SAL and LAL individually housed mice showed more total and open arm entries than group-housed LAL mice, confirming the hyperactivity of individually housed mice and suggesting that isolation had no clear anxiolytic or anxiogenic actions. In the water-maze, we compared the performance of individually housed SAL, individually housed LAL mice, and group-housed LAL mice treated with nicotine (0.35 and 0.175 mg/kg) or vehicle. Nicotine did not improve acquisition in group-housed mice and even impaired it in individually housed mice. Retention of platform position was better in vehicle-treated individually housed mice in comparison with vehicle-treated group-housed mice. The present study demonstrates that housing conditions but not level of aggressiveness modify spontaneous locomotor activity and behaviors displayed on the elevated plus-maze test, and can also influence retention of a spatial learning task.

Follow up after primary treatment: curable diseases primarily treated with surgery

There is considerable debate at the present time concerning the role and relevance of follow-up following primary surgical treatment with curative intent in patients presenting with cancer. There are many factors which govern the aims of follow-up programmes and also the determinants of success of individualised follow-up. Clearly different tumour types have different levels of aggressiveness and will therefore have differing disease-free interval and survival figures. Even if one looks at individual cancer types, taking breast cancer as an example, prognosis will depend on many factors such as grade, stage and size of tumour. The primary aim of follow-up is to detect at an early stage either local or systemic recurrence of the primary rumour. The second aim of follow-up is to detect new primary cancers of the contralateral side or in specific cancers to look for other cancer types which occur more commonly in patients who were diagnosed with specific primary cancers. In certain instances follow-up is also designed to look for complications after primary treatment and finally there is a body of opinion to suggest that follow-up is of benefit in the management of psychological problems which occur in patients with a diagnosis of cancer. The real issue at stake when developing protocols for follow-up is an assessment of the determinants of success. Foremost is the extent to which follow-up programmes will detect either local or systemic recurrence. Furthermore, the issue relates to whether such recurrences are detected at the time of the visit to the follow-up clinic or in fact are found by the patient who is then referred by the GP to the follow-up clinic with a suspected recurrence. This raises the important point of the cost of follow-up. The cost effectiveness of follow-up in cancer is very difficult to determine as it is almost impossible to match cost of follow-up with the increased number of years of survival in each case. Finally it makes sense to match the frequency of follow-up with the risk of recurrent disease — the greater the risk of recurrence then the greater should be the frequency of follow-up. In determining protocols therefore, it seems logical that each patient should be individualised, or each risk category of every cancer should be categorised, according to risk of recurrence. One obvious example of this would be whether follow-up of patients with ductal carcinoma in situ of the breast should be different from those with invasive adenocarcinoma of the breast. Whilst it seems logical to follow this schedule, there are major practical difficulties in individualising follow-up programmes according to levels of risk. Therefore, in deciding on frequency of follow-up there must be a balance between determining risk of recurrence and also deciding what type of follow-up programme is manageable and easy to follow in individual units.

Intraspecific colony recognition in the termites Macrotermes subhyalinus and Macrotermes bellicosus (Isoptera, Termitidae)

Intraspecific colony recognition in the termites Macrotermes subhyalinus and M. bellicosus was investigated over two field seasons in Comoe-Nationalpark (Ivory Coast). Behavioural tests with major workers and minor soldiers, respectively, were performed using neutral arenas of covered plastic dishes. For each species, termites were sampled by baiting from 10 field colonies randomly chosen at four different sites. Major workers and minor soldiers of both species were capable of differentially discriminating between members of various colonies. In major workers of M. subhyalinus this discriminatory ability was expressed as varying degrees of aggression, whereas major workers of M. bellicosus showed different degrees of examination behaviour. Minor soldiers of both species reacted to foreign colony members with different levels of aggression. Thus, M. bellicosus displayed a more subtle form of discriminatory behaviour. Mound volume was measured as a parameter for colony size and stage of colony development. Aggression (in major workers of M. subhyalinus) and examination behaviour (in major workers of M. bellicosus) were not correlated with differences in mound volume and thus differences in size or age of the involved colonies. Aggression and examination behaviour respectively of major workers were not correlated either with the spatial distance between the colonies. We found cases, where individuals from neighbouring colonies showed either no aggression/examination behaviour or a high level of aggression/examination behaviour. Thus, there was no indication of a dear-enemy phenomenon. The behaviour of colony discrimination was found to be consistent over the two years for both species.

Aggressiveness of Stagonospora nodorum Isolates Obtained from Wheat in the Northern Great Plains.

Isolates of Stagonospora nodorum, obtained from diseased wheat leaves collected in fields in Montana, North Dakota, and South Dakota, were tested on detached seedling leaves of wheat and found to be pathogenic. Differences among isolates chosen at random were detected in the first phase of the inoculations. Isolates associated with severe and mild symptom severity, as measured by lesion size, were selected in phase two. Isolates associated with severe and mild symptom severity were statistically differentiated in phase three. The ability of isolates to cause significant differences in symptom severity was interpreted as differences in aggressiveness. The differences among isolates detected with detached leaf experiments was confirmed with glasshouse inoculations of seedling wheat plants. The high aggressive isolates consistently produced higher symptom severity on wheat seedlings, as measured by percentage necrosis, than low aggressive isolates. Cultivars were consistently differentiated with isolates associated with different levels of aggressiveness. With unselected isolates, the cultivar × isolate interaction was nonsignificant, indicating a lack of specificity. With high and low aggressive isolates, the cultivar × isolate interaction was significant. Considering that the magnitude of the mean squares for interactions were rather low compared to the main effects, it is speculated either that specificity is detected with the present isolates but only at a low level, or that specificity is apparent only when isolate extremes are tested. With studying isolates in phases rather than random comparisons, fungal isolates associated the high and low aggressiveness can be identified and, once identified, isolates from different hosts or geographical areas can be compared in an efficient and meaningful manner.

The Influence of Temperature and Light on Defoliation Levels of Elm by Dutch Elm Disease

ABSTRACT The amount of defoliation of elm (Ulmus procera) caused by three Ophiostoma novoulmi Eurasian race isolates over 14 seasons of field trials was found to be strongly correlated with mean air temperature and mean number of sunshine hours over the 12-week period from inoculation to assessment, and with tree age. The coefficient of determination for the regression of percent defoliation on the environmental and tree factors was 0.76, P < 0.001 (33 df). Levels of defoliation were greatest when mean air temperatures exceeded 17 degrees C with moderate light (5 to 7 h of sunshine), and lowest under conditions of either high light (>7.5 h of sunshine) at all air temperatures or low light (<4.5 h of sunshine) and air temperatures of less than 15.5 degrees C. The model varied in its intercept for the three isolates, reflecting their different levels of aggressiveness. The role of environmental factors in the development of Dutch elm disease symptoms and the implications for elm resistance breeding are discussed.

Car-Driver Models for Manual and Automated Travel

This paper presents a model for manual and automated traffic flow. The model is based on the abstraction of vehicle activities by the space and time taken up by the vehicle engaged in the activity. The manual driver model includes the activities of vehicle following and lane change and allows for different levels of aggressiveness of drivers. The parameters of the activities are calibrated with real highway data. The expectation is that this model will provide more realistic estimates of highway capacity while retaining the efficiency of macro-scale simulators.

IMMUNOHISTOCHEMISTRY IN ORAL PATHOLOGY

SUMMARY Immunohistochemistry has added a new dimension to diagnostic pathology by improving diagnostic accuracy. Identification of poorly differentiated carcinomas, melanoma, lymphomas, and various sarcomas is among the most important applications in tumor immunohistochemistry. The use of antibodies to prognostic markers, such as nuclear proliferation antigens, is likely to improve our capability to separate tumors of different levels of aggressiveness within various histologic categories.

Behavioral and hormonal correlates of alternative reproductive strategies in a polygynous lizard: Tests of the relative plasticity and challenge hypotheses

Species with alternative reproductive tactics are good models to investigate the poorly understood question of whether individual variation within sexes results from the same physiological mechanisms that control variation between sexes. We have shown previously that adult male tree lizards, Urosaurus ornatus, of different throat color morphs express different levels of aggression in the laboratory. Further field results support the suggestion that the two morphs practice alternative reproductive tactics because the two morphs express different levels of aggressive behavior under field conditions and exhibit dramatic and opposite responses to aggressive challenges. However, despite these behavioral differences, the two morphs do not differ in levels of testosterone or corticosterone either in undisturbed situations or following aggressive challenge. These results are consistent with the relative plasticity hypothesis which proposes that organizational, rather than activational, actions of steroid hormones will be more important in morph differentiation when morphs are fixed in adult life, as they are in tree lizards. These results also support the hypothesis that steroid hormonal levels are insensitive to social modulation in males of species such as U. ornatus without paternal care.

Aggressiveness of Isolates ofPyrenophora tritici-repentisObtained from Wheat in the Northern Great Plains

Eighty-four isolates of Pyrenophora tritici-repentis, obtained from diseased wheat leaves collected from fields in Montana, North Dakota, and South Dakota, were tested on detached seedling leaves of wheat. All isolates were pathogenic. Different levels of aggressiveness were detected among isolates when randomly compared. Isolates with apparent-high levels of aggressiveness were found to be widespread over the region, whereas isolates with apparent-low levels of aggressiveness were detected at a lesser frequency (...)

Variability inSeptoria musivain Aggressiveness

Krupinsky, J. M. 1989. Variability in Septoria musiva in aggressiveness. Phytopathology 79:413-416. In growth studies on five different culture media, spore production of North Dakota, South Dakota, and Minnesota. Isolates with high and low Septoria musiva was best on V-8 juice with phytone peptone agar and yeast levels of aggressiveness were selected from the local leaf isolates, the local malt extract agar. A spore concentration of 1 X 106 spores/ml and an canker isolates, and the regional leaf isolates and compared. High and low incubation time of 48 hr were found to promote good symptom develop- levels of aggressiveness were confirmed for the three types of isolates. ment in glasshouse inoculations. Different levels of aggressiveness were Canker isolates were found to be as aggressive as leaf isolates. The local leaf detected for S. musiva in glasshouse inoculations of five Populus clones and local canker isolates were found to be as aggressive as isolates that were with local leaf isolates, local canker isolates, and regional leaf isolates from obtained from a more widespread geographic area.

Ethanol effects on aggression of rats selected for different levels of aggressiveness

Male rats confronting strange male intruders into their home cages were divided into nonaggressive, low-to-intermediate aggressive, and highly aggressive groups. In tests with low (0.3 and 0.6 g/kg) doses of ethanol the nonaggressive rats did not become aggressive; low-intermediate animals showed a significant increase in frequency and duration of attack behaviors; but highly aggressive rats displayed a slight (nonsignificant) decline. A higher ethanol dose (1.2 g/kg) consistently led to decreased aggression. This rate-dependency of the enhancement of aggression by low doses of ethanol is concordant with a view that the mechanism of this enhancement involves ethanol interference with some mechanism which normally acts to limit or inhibit attack.

Differences in the capacity of male odours to affect investigatory behaviour and different urinary marking patterns in two strains of mice, selectively bred for high and low aggressiveness.

The investigatory behaviour of male and female mice on sawdust soiled by male mice with different levels of aggressiveness was studied in two experiments. To investigate whether high and low aggressive males show different urinary marking patterns, a third experiment was set up. The strains TA(Turku Aggressive) and TNA (Turku Nonaggressive) have been developed by selective breeding. The TA-soiled bedding discouraged investigation by male mice, while females avoided TNA-soiled areas. Also the urine marking patterns differed between the high aggressive TA and low aggressive TNA males. The results indicate that the urine marking behaviour and the odour communication system in the TA and TNA males correlate with their hereditarily determined disposition for aggressive behaviour.

Influence of the estrous cycle on heterosexual aggression in two strains of rats (S 3 and WEzob)

Two strains of rats (S 3 and WEzob), which show different levels of aggression in the laboratory, were tested in repeated heterosexual confrontations. Daily 15-min observations were made of the interactions between a female throughout a complete estrous cycle and the same male partner. In both strains the topography of aggression was similar in males and females, but the frequency of specific parameters varied. Males showed more offensive and females more defensive patterns. The overall level of aggression was very low on the day of estrous, when the female was sexually receptive. There were no differences in any elements of female or male behavior between the other 3 days of the cycle. The results support previous conclusions from single-sex encounters that in rats there is no sexual dimorphism in the ability to show aggression.

Behavioral consequences of agonistic experience in rats: Sex differences and the effects of testosterone.

The effects of winning or losing on subsequent aggressive behavior in male and female rats were studied. By using three strains of rats with different levels of aggression, a procedure was developed to create winners and losers. Subsequently, winners were tested against losers. Behavioral analysis of all tests enabled a thorough study of these processes and of their consequences. The results indicate that significant and relatively permanent behavioral changes are induced in intact and castrated, testosterone-treated males but not in females. The results suggest that behavioral inhibition is a specific characteristic of the male's agonistic behavioral repertoire.

Reproductive Importance of Dominant Male Greater Prairie Chickens

THE breeding display of Greater Prairie Chickens (Tympanuchus cupido pinnatus) has been described by several authors (Breckenridge 1929, Bent 1932, Hamerstrom 1941, Schwartz 1945, Hamerstrom and Hamerstrom 1960, Robel 1964). All mentioned the importance of aggressive behavior and territoriality during the display season. Previous research on Prairie Chickens in Kansas has shown that socially dominant males are responsible for most copulations on booming grounds (Robel 1970). Mating success of males has been correlated with social rank, which was characterized by different levels of aggression (i.e. dominant males highly aggressive). During 1970 and 1971 we studied the importance of dominant males within a stabilized booming ground social organization, especially as related to reproductive success. Our study involved observing male and female behavior both before and after the removal of dominant males from a booming ground.

Factors Affecting Age Ratios of Samples of Canada Geese Caught with Cannon-Nets

Widely differing opinions are held concerning the reliability of age-ratio statistics derived from samples of Canada geese trapped with cannon-nets. The 95 percent confidence limits of an age-ratio estimate of 41.3 percent immature derived from 35 catches involving 2,451 geese were 35.3-50.5 percent immature. These data indicate the potential for error when such data are used to analyze population dynamics. Based on a study of behavior of marked Canada geese of all ages and sexes and family units, utilizing radio telemetry, reasons are suggested for age-ratio fluctuations of cannon-net trap samples. Important interrelated factors causing such cannon-net trap age-ratio differences are time of year, time of day, food availability, behavior changes, length of time on bait, and weather. When these factors cause Canada geese to crowd densely onto a baited-trap site, a higher percentage of adults would usually be obtained than when trap catches represent different levels of aggression, family defense, and less crowded conditions. Alternative explanations are offered of data that led Funk and Grieb (1965) to conclude that age ratios from baited-trap samples reliably indicate population structure-a conclusion different from that reached in this paper. Realistic estimation of sex and age composition of a population provides the axiomatic necessary foundation for evaluating and understanding past reproductive successes which in turn provide the basis for predicting future population fluctuations. Predicting the size of an ensuing year's population is an important aspect of the management of Canada geese (Branta canadensis interior) in the Mississippi Flyway, for the legal hunter-harvest is calculated as a percentage of geese expected to make up the coming year's population. This estimate is based upon many factors, one of the more important being the estimate of the age composition of the population that returned in the spring to the breeding grounds. Throughout the United States, cannonnet trapping (Dill and Thornsberry 1950, and many subsequent technique modifications) is one of the major methods, and often the only method, used to capture Canada geese during the migration and winter periods. Many persons who have done considerable goose trapping with cannon-nets have learned that age ratios of individual catches may fluctuate greatly and, as a result, place little confidence in the use of such age ratios in population dynamics analyses. Until recently, however (Nass 1964, Funk and Grieb 1965), little statistical or methodological examination of age-ratio data from trap samples has been reported, and only tentative explanations have been offered of possible factors influencing such age-ratio fluctuations or biases. The purpose of this paper is to present an evaluation of the variability of trap-sample age ratios obtained from 35 cannon-net c tches involving 2,451 Canada geese (nearly all B. c. interior). Based on a study of Canada goose behavior including observations of marked individuals of all ages and sexes and family groups at bait sites, explanations are offered as to why age ratios of cannon-net catches may vary rather widely. Results are part of a more comprehensive study of Canada goose behavior in winter, utilizing radio telemetry. The program was supported chiefly by the National Science Foundation (GB-623); additional support was provided by the Cooperative Wildlife Research Laboratory, Southern Illinois Univ rsity, for which I am indebted to Dr. W. D. Klimstra, Director. Findings are