Different Patterns Of Behavior Research Articles

Differences in behavioral patterns and resistance to stress-induced gastric ulceration between August and Wistar rats adapted and unadapted to hypoxia

The incidence of gastric ulceration induced by acute emotional stress in Wistar rats is 3 times higher than in August rats, and the mean number of gastric ulcers in Wistar rats 6.3-fold surpassed that in August rats. Wistar rats predisposed to stress-induced ulceration displayed suppressed locomotor and exploratory activities in the open field test, while August rats had more stable behavioral patterns and enhanced exploratory activity after stress. Short-term preadaptation to hypobaric hypoxia for 6 days attenuated stress-induced gastric ulceration, whereas long-term adaptation (40 days) aggravated the severity of gastric ulcers in August and Wistar rats. The interstrain differences in stress-induced ulceration persisted after adaptation. The data suggest that these differences are related to genetically determined peculiarities of production and metabolism of NO and glucocorticoids in August and Wistar rats.

Effects of forest fragmentation on behaviour patterns in the eastern chipmunk (Tamias striatus)

We examined behaviour in adult eastern chipmunks (Tamias striatus) from 1992 to 1995 in a landscape altered by forest clear-cutting in central Pennsylvania, U.S.A. Our objective was to compare behaviour patterns in chipmunk populations occupying mature continuous forest versus mature forested corridors (100 m wide) surrounded by clearcuts. Chipmunks spent a significantly greater proportion of their time pausing in the forested-corridor habitat than in the continuous-forest habitat. In addition, chipmunks spent less time locomoting and foraging in the forested-corridor habitat than in the continuous forest. We attributed differences in behaviour patterns between chipmunks in the two forest types primarily to the influence of forest fragmentation on the risk of predation and to the availability of food resources.

Acoustic discrimination of two zooplankton species (mysid) at 38 and 120 kHz

Using bifrequency sonar (38 kHz, 120 kHz) directed towards the open sea from the inside of a submarine cave, two species of Mysidacea (Crustacea), similar in shape but not in size, and with different patterns of behaviour, were observed simultaneously and discriminated, and their biomass was estimated during their migration. The first species, Hemimysis speluncola (<1 cm length), lives in the submarine cave, forming a distinct community that migrates horizontally. The second species, Siriella jaltensis (>1 cm length), lives in the open sea and migrates vertically. These species are both detected clearly at 120 kHz, but only the larger one, Siriella jaltensis, is detected at 38 kHz. This distinction allows one to determine the size limits of planktonic objects detected at these frequencies, i.e. 3 mm at 120 kHz and 10 mm at 38 kHz, corresponding to one quarter of the wavelength. The target strength (TS) of each species was calculated from the field data and compared to results calculated from three models. As the volume of the cave occupied by the Hemimysis population is about 300 m 3, and the density of the swarm is 36,000 individuals/m 3, the number of individuals in the cave is estimated to be around 10 million (or 24 kg). The density of the open-water population of Siriella is estimated to be 13 individuals/m 3.

Ecology of tropical hermit crabs at Quirimba Island, Mozambique:shell characteristics and utilisation

The use of gastropod shells by hermit crabs at Quirimba Island, Mozambique, was investigated. Particular attention was paid to the upper shore/supralittoral zone species Clibanarius longitarsus, Coenobita cavipes and Coenobita rugosus. The study area is characterised by a high diversity of gastropod species as well as hermit crabs. Supralittoral hermit crabs were little, if at all, resource restricted due to concentration of empty shells on the strandline and shell middens created by local people. The range of the 3 study species overlaps substantially and each uses a wide range of shell types. Shore habitat, shell abundance and availability were found to have little influence on shell use. With increased tidal emersion/terrestrial nature (for a given crab mass), total diversity of shells used increased, shell mass carried decreased, damaged shell use decreased and carried shell fit increased. The architecture and strength of shells used, however, followed more complex individual species characteristics and behaviour patterns. Species specific differences in behavioural patterns may be important for shell resource partitioning.

The relationship between stress-coping and vasomotor symptoms in postmenopausal women

Objective: The objective was to assess whether menopausal women with vasomotor symptoms had a lower stress-coping than menopausal women without symptoms and if stress-coping changed when vasomotor symptoms had been effectively treated with estrogens. The objective was also to assess whether menopausal women, effectively treated for vasomotor symptoms, had a higher neuroticism score than women without such symptoms. Methods: Two groups of physically and mentally healthy postmenopausal women were recruited from the outpatient clinic at the Department of Obstetrics and Gynaecology, University Hospital of Linköping, Sweden. Sixteen women with vasomotor symptoms (target group) were treated with oral 17 β-estradiol, 2 mg/day during 3 months. A comparison group was formed comprising 17 women without vasomotor symptoms. The Kupperman Index was used to cover menopausal characteristics in all women at baseline as well as at the second visit after 3 months. Stress-coping was measured by means of the Stress Coping Inventory, which is an instrument developed to measure of the individual's appraisal of having adaptive resources for handling stressful situations. At the second visit all women were also asked to complete the Eysenck Personality Inventory. Results: Women in the target group had a significantly lower stress-coping than women in the comparison group at baseline as well as after 3 months. Stress-coping did not change after estrogen therapy, although the vasomotor symptoms had virtually disappeared. Women in the target group successfully treated for vasomotor symptoms, had a significantly higher neuroticism score compared to the comparison group. Conclusions: Differences in behaviour patterns and personality are probably two reasons why some women report or seek advice due to vasomotor symptoms and some women do not. Stress-coping in women with moderate to severe vasomotor symptoms is unaffected by estrogens.

The Reactions of α-Phosphoryl Sulfoxides With Ortho- and Para-Quinones. Synthesis of α,β -Unsaturated Sulfoxides and Aryl 1,2-x-Fused onto Furan Rings

The reactions of α-phosphoryl sulfoxide 3 with o-quinones 1a-c were found to react in different pathways to give either the mono-olefin 4 (from 1a) or the corresponding [1,2-x]-fused dihydrofuran 8 (from 1b) or 9 (from 1c). Conversely, a completely different pattern of behaviour was observed for 3 toward the p-quinones 2a and 2b, whereby 2-(4-hydroxyaryl)-1,2-bis(methyl sulfoxide) ethyl diethyl phosphonate derivatives 11 and 12, respectively, were the products.

The Evolution of Conformist Transmission and the Emergence of Between-Group Differences

Unlike other animal species, much of the variation among human groups is cultural: genetically similar people living in similar environments exhibit strikingly different patterns of behavior because they have different, culturally acquired beliefs and values. Such cultural transmission is based on complex, derived psychological mechanisms that are likely to have been shaped by natural selection. It is important to understand the nature of these evolved psychological mechanisms because they determine which beliefs and values spread and persist in human groups. Boyd and Richerson showed that a tendency to acquire the most common behavior exhibited in a society was adaptive in a simple model of evolution in a spatially varying environment, because such a tendency increases the probability of acquiring adaptive beliefs and values. Here, we study the evolution of such “conformist transmission” in a more general model in which environments vary in both time and space. The analysis of this model indicates that conformist transmission is favored under a very broad range of conditions, broader in fact than the range of conditions that favor a substantial reliance on social learning. The analysis also suggests that there is a synergistic relationship between the evolution of imitation and the evolution of conformism. We conclude by examining the role of conformism in explaining the maintenance of cultural differences among groups.

The reflective practice of design teams

The aim of our studies is to develop tools and guidelines to improve team design practice. In order to improve team designing, we have to understand it, in order to understand we must be able to analyze and describe it. To describe the nature of team designing, we developed a new description method, based on Schön's theory of reflective practice. This method was tested by applying it in the description of the activities of two design teams. The description method proves to be very useful, in that it allows a concise description of a design project in which the elements vital to the understanding of the design progress are conserved. Comparing the obtained descriptions of these two teams designing reveals different patterns of behaviour. These patterns of behaviour arouse an interest in a more detailed and in-depth analysis of team design behaviour.

Enzymatic and morphometric analyses in mediterranean populations of the rose shrimp, Aristeus antennatus (Risso, 1816)

Eleven samples of rose shrimp ( Aristeus antennatus) from different areas of the Mediterranean Sea and adjacent Atlantic waters were subjected to morphometric and electrophoretic analyses. The object was to characterize possible population differences that would account for previously reported differences in behavioural patterns observed in commercial fishing activity. Genetic analysis of 27 enzyme systems yielded only fifteen useful loci of which fibre had allele variants, but only two of them were polymorphic within 95%. Morphometric analysis of nine body and appendage measurements revealed significant differences between sampling sites in scaphocerite length, uropodal length, and the length of the articles on the third walking leg. The samples analysed genetically could not be differentiated, but morphological differences were compared between different hydrographic regions of the Mediterranean Basin.

ETHOSYS (R)—new system for recording and analysis of behaviour of free-ranging domestic animals and wildlife

A storage telemetry system has been developed to monitor domestic animals and wildlife, and has been tested under variable conditions on sheep, Przewalski horse and mouflon. It can be used for automatic recording of different patterns of behaviour, such as activity and feeding, and is based on advanced analysis of sensor-emitted signals. The system is made up of collars (ETHOREC) with sensors and electronic devices for behaviour recording, a central station (ETHOLINK) and software for data transmission and processing (ETHODAT). All components of the ETHOREC recording device are integrated in the collar. Long-time recording of behaviour through up to four different channels and in numerous animals at one and the same time are necessary elements to facilitate biorhythmic analysis of animals under free-ranging conditions. The results obtained from this telemetry system were compared with visual observations on six sheep and four Przewalski horses. Parallel recordings were taken from four sheep, using a recorder for jaw movements. Locomotor activity usually was rated somewhat higher by observers, whereas feed uptake was rated lower. Higher feed uptake values were measured by means of the jaw movement recorder, although deviations thus measured varied less than those noticed by visual observations. All measured series exhibited significant correlations with control values. The system, consequently, was found to be more suitable for determination of diurnal patterns, change over time and relative comparison between behaviour levels than it actually was for measurement of absolute duration of a given behaviour.

Sexual and social experience is associated with different patterns of behavior and neural activation in male prairie voles

Monogamous prairie voles ( Microtus ochrogaster) show mating-induced aggression towards conspecific strangers. This behavior is both selective and enduring. The present study was designed to investigate the behavioral conditions for the emergence of selective aggression (by varying prior experience with a female and identity of intruders) and the limbic activation in response to an intruder (by mapping regional staining for c- fos) in male prairie voles. In a first experiment, males that mated with a female for 24 h exhibited aggression towards a male intruder and had more Fos-immunoreactive (Fos-ir) cells in the medial amygdala (AMYGme) and medial preoptic area (MPO) relative to males that cohabited with a female without mating or that had no prior exposure to a female. Cohabited males did not become aggressive. However, these males along with mated males had an increased number of Fos-ir cells in the lateral septum (LS) and the bed nucleus of the stria terminalis (BST) relative to males without prior exposure to a female. In a second experiment, mated males exhibited more offensive aggression to a male intruder but more defensive aggression to a female intruder. Both types of aggression, however, induced an increase in the number of Fos-ir cells in the AMYGme. In addition, Fos-ir staining in the BST was induced selectively in response to a male intruder and a similar trend was found in the LS. Exposure to a male or female intruder did not increase Fos-ir staining in the MPO. Taken together, our data suggest the neural substrates activated by social/sexual activity and involved in response to intruders. The AMYGme was involved in processing intruder-related cues and/or in the regulation of aggressive response to both male and female intruders. The BST and LS were modulated by social experience with a female (mating or cohabitation) and were responsive to male-related cues even in the absence of aggression. Finally, the MPO was activated at different magnitudes by social or sexual experience but did not respond to intruder-related cues as measured by Fos-ir.

Conservation headlands: effects on butterfly distribution and behaviour

The gamebird management system known as Conservation Headlands, whereby the outermost 6 m of cereal fields are selectively sprayed, is known to affect the distribution and abundance of many non-game species including butterflies. Previous work on butterflies in the arable environment showed that more butterflies were found associated with field margins which had received reduced pesticide inputs, but only speculated on the mechanism which produced the enhanced numbers. This study examines the differences in butterfly behaviour between field margins with conservation headlands and those sprayed according to normal farm practice. The results show distinct within-season differences in behaviour patterns. Spring emerging butterflies in field margins sprayed according to normal farm practice are principally associated with the field boundary habitat (the hedgerow), whilst those in fields with conservation headlands are principally associated with the headland. The proportion of time spent in flight, feeding, resting and mate location behaviours also changed with headland regime. In normally sprayed field margins the principal activity was flight, in field margins with conservation headlands this dominance was broken with striking increases in foraging activity on headland flora. Butterflies that emerged in the summer were less strongly associated with the headland than those that emerged in the spring. The discussion relates these differences to the changing nature of the flora of the field boundary and headlands over the season and the population structure of the species studied. The role of resource provisioning for non-target species in the arable environment, and the effect of resources on landscape permeability to dispersing individuals are also discussed.

Determinants of regular source of care among homeless adults in Los Angeles.

The authors explore the determinants of having a regular source of care in a community-based probability sample of homeless adults in Los Angeles. Results from this study should be more representative than those from previous studies of the homeless that are clinic- or shelter-based. In addition to those factors found to be barriers to regular sources of care in the general population, we hypothesized that psychosocial characteristics of the homeless and the homeless lifestyle would negatively impact their likelihood of having a regular source of care. The authors conducted a multiple logistic regression to predict regular source of care among the homeless, using an adaptation of the Behavioral Model of health services utilization as an analytic framework. Fifty-seven percent of the sample reported that they had a regular source of care. Of those with a source of care, 30% reported a hospital outpatient department; 25% reported a community or homeless clinic; 23% reported a hospital emergency room; 14% reported a government clinic; and 9% reported a private physician's office as their source of care. Some factors found to be barriers to having a regular source of care in the general population (male, Hispanic, young age) also were barriers among homeless adults. Additional barriers in this sample included homelessness-related characteristics such as competing needs, long-term homelessness, and social isolation. Chronic mental illness and chronic substance dependence were not related to having a source of care among the homeless. Characteristics that increased the likelihood of having a regular source of care in the general population (poor health status, Medicaid) were not related to having a regular source of care among the homeless. In a context of limited resources, the distribution of regular source of care among the homeless appears to be highly inequitable. Although some of the characteristics identifying those with a regular source of care suggest differential patterns of behavior across subgroups, others suggest differential advantage in access to care and a lack of fit between the needs of the homeless and the organization of health services.

Patterns of health-compromising behaviors among Minnesota adolescents: sociodemographic variations.

This study compared prevalence rates of health-compromising behaviors among boys and girls from different ethnic backgrounds in early, middle, and late adolescence and compared co-occurrences of such behaviors across gender and ethnic groups. The study population included 123 132 adolescents in grades 6, 9, and 12. Adolescents completed a classroom-administered statewide survey focusing on high-risk behaviors, including unhealthy weight loss, substance abuse, suicide risk, delinquency, and sexual activity. Prevalence rates of most health-compromising behaviors differed by gender, increased with age, and tended to be highest among American Indian youth and lowest among Asian Americans. Strong associations were found between substance abuse and delinquency across all ethnic groups. Substance abuse and delinquency were associated with suicide risk across most ethnic groups. Covariations with sexual activity and unhealthy weight loss behaviors showed more ethnic variation. Prevention interventions should take into account the tendency for health-compromising behaviors to co-occur and should be sensitive to demographic and socioeconomic differences in behavior patterns.

Malignant melanoma risk factors by anatomic site: a case-control study and polychotomous logistic regression analysis.

This population-based case-control study systematically examined reported malignant melanoma risk factors by anatomic site. Study subjects consisted of 548 invasive melanoma cases diagnosed in Connecticut during 1987-1989 and 494 randomly selected controls. Multivariate polychotomous logistic regression was used to determine whether risk factors differed across anatomic sites. Risk factors examined included demographic and pigmentary characteristics, sun exposure-related factors, anatomic site-specific sunburn, recreational water activity clothing habits and number of nevi. A pattern of site-specificity was observed for sunburn. A history of sunburn at an anatomic site was specifically related to the development of malignant melanoma at that site more so than at other sites. This site-specificity was consistent with a direct role for intense, intermittent sun exposure in the development of melanoma. Age and gender were the only risk factors that differed significantly in effect across anatomic sites. The age difference was explained by differences in histologic subtype across sites. The gender difference could not be explained by sex differences in anatomic site-specific sunburns or in recreational water activity clothing habits. Alternative explanations include sex differences in behavioral patterns of sun exposure that we did not measure and as yet unelucidated differences in susceptibility to melanoma according to sex and anatomic site.

How to recognize risk prone adolescent girls?

Background Lack of positive feminine self-esteem, previous risk behaviour and inadequate home support are likely to disturb a safe and satisfactory initiation of sexual life. A study was performed to recognize girls needing extra counseling in gynecological clinics of low risk population. Methods 245 girls, 13–19 years of age, who attended the out-patient adolescent, gynecologic clinic of Folkhalsan between 1989–94 were studied. A semistructured interview including developmental circumstances, sexual and social behavior and actual life situation, was developed and conducted at the time of the first visit lasting one hour. On this basis the girls were divided into 5 group and have been followed-up for a mean of 1,4 years. Results 27% of the girl showed a high degree of risk prone behavior (e.g. heavy drinking) or attitudes and were classified as risk prones. 23% had a problematic life situation or lacked adequate family support and were classified as support-needers. During follow-up all unwanted pregnancies and 87% of STD:s occurred in these two groups. Negative attitudes to sexuality and need of excessive behavioral control were prevalent in 9% of the girls, classified as negative-feminines. They had a low degree of sexual activity. A good self-esteem and responsability was found in 20% of the girls, classified as positive-feminines. They had no pregnancies nor STD:s during follow-up. Finally, 20% of the girls were not possible to classify, and were called non-defineds. Conclusions Adolescent girls apparently express different patterns of behavior to solve their developmental crisis. This study shows that about half of the girls attending an adolescent gynecologic clinic, may have problems requiring extra social, psychosexual and behavioral counseling. A focused interview facilitates the identification of such cases.

An Empirical Investigation of the Formation and Implications of the Organizational Buyer's Strategic and Tactical Roles

Although research in organizational buying behavior has alluded to the importance of the purchasing agent's enacted role in the development and execution of an organization's procurement related activities, there exists little corresponding empirical evidence. This paper examined the buyer's self-perceived role, factors that affect its formation, and the impact that a buyer's role definition has on various aspects of buying behavior. Cluster analysis is employed to differentiate among purchasing agents based on their perceived participation in various stages of the purchasing decision process. Different patterns of behavior emerge from the five empirically derived clusters. These differences are presented and the managerial implications are discussed.

Surface freezing and surface-phase behaviors in binary mixtures of alkanes

X-ray surface scattering and surface tension measurements reveal surface freezing in molten mixtures of alkanes of two different lengths. A crystalline monolayer is formed at the surface a few degrees above the bulk freezing temperature. The structure of the monolayer has been determined on an angstrom scale. Two widely different patterns of behavior emerge, which depend on the length difference of the two components, Δ n. For small Δ n the surface properties and structure vary continuously with concentration. For large Δ n, however, the variation is discontinuous, exhibiting surface segregation. Furthermore, a new surface crystalline structure appears for a well-defined range of compositions and temperatures, and surface freezing is completely suppressed for another range. A Flory—Huggins theory based on competition between entropic mixing and a repulsive interaction due to chain length mismatch accounts well for the observed phenomena.

Modeling of cardiovascular variability using a differential delay equation.

The influence of time delay in the baroreflex control of the heart activity is analyzed by using a simple mathematical model of the short-term pressure regulation. The mean arterial pressure in a Windkessel model is controlled by a nonlinear feedback driving a nonpulsatile model of the cardiac pump in accordance with the steady-state characteristics of the arterial baroreceptor reflex. A pure time delay is placed in the feedback branch to simulate the latent period of the baroreceptor regulation. Because of system nonlinearity model dynamics is found to be highly sensitive to time delay and changes of this parameter within a physiological range cause the model to exhibit different patterns of behavior. For low values of time delay (shorter than 0.5 s) the model remains in a steady state. When time delay is longer than 0.5 s, a Hopf bifurcation is crossed and spontaneous oscillations occur with frequencies in the high-frequency (HF) band. Further increases of time delay above 1.2s cause the oscillations to become more complex, and following the typical Feigenbaum cascade, the system becomes chaotic. In this condition heart rate, and flow show evident variability. The heart rate power spectrum exhibits a peak whose frequency moves from the HF to LF band depending on whether simulated time delay is as short as the vagal-mediated control or long as the sympathetic one.

Fully plastic ductile tearing of HY130 steel—an analysis by J, COD, energy rate and crack opening angle

The dependence of J-R curves on size of test piece is examined for fully plastic deep notch bend (DNB) tests on HY130 steel, taken to large amounts of ductile crack growth (60 per cent of the ligament) for a range of initial widths at 20 mm thick and one geometrically similar size, 50 mm thick. The object is to understand the cause of the widely different patterns of behaviour that have been reported in the literature, even within the DNB type of configuration. In the present tests, the proportion of shear lip is the same for the geometrically similar pair but the J-R curve for the 50 mm thick piece is much lower than for the similar piece, 20 mm thick. The rate of change of displacement, dq/da, is analysed using the factor. r∗, that defines the instantaneous centre of rotation at each step of growth, to give a measure of crack tip opening angle (CTOA), xg. After an initial transient regime of small growth, xg and r∗ remain constant. The normalized load. L, rises due to work hardening during crack growth by amounts that depend on size while xg and r∗ vary mildly with initial width to give an appreciable variation of the combined term Lxg/r∗, which is the factor that controls the behaviour of the JR curves. It is speculated that CTOA and its variation with configuration (as seen in the literature) may, for large growth, assume the role of the two parameters suggested in recent literature as controlling the variation of toughness with constraint.