Juvenile Behavior Research Articles

タナバタウオ Plesiops coeruleolineatus （タナバタウオ科）の繁殖行動，卵発生および仔稚魚の形態変化

タナバタウオ Plesiops coeruleolineatus （タナバタウオ科）の繁殖行動，卵発生および仔稚魚の形態変化

Domestic violence as a risk factor for the occurrence and development of behavioural disorders in children

Exposure to a traumatic event such as domestic violence has many negative consequences. The subject of this paper is the behaviour disorder of children as a consequence of domestic violence as a risk factor. The paper is based on a case study of the centre for social work. The case of domestic violence, identified consequences and actions undertaken by the center has been analysed. Along with a brief overview of the etiological explanation, the paper gives an overview of the connection between victimization of a child by domestic violence and the manifested behavioural disorder of a chuld. This is done on a concrete example of a family in which violence is present, which is witnessed by the child who shows behavioural disorder. The nalysis indicates violence as a risk factor for juvenile behaviour disorder and delinquency. Therefore, importance of a comprehensive approach within social protection and education systems to children with behavioural disorders is pointed out.

Just Say No: Dr Richard I. Evans Efforts to Influence Juvenile Behaviour through US Public Health Programming

Television as a means of distributing public health information and influencing health behaviours was recognized even in the earliest days of broadcasting, a natural extension of health messaging on radio and film. This paper examines the place health-focused programming held in the United States’ educational television landscape and the role of Dr Richard I. Evans, social-psychology researcher, who sought to use television to influence the behaviours of youths engaging in “risky” activities.

Reduction of histamine and enhanced spinning behavior of Daphnia magna caused by scarlet mutant.

The ABC transporter, Scarlet, and its binding partner, White are involved in pigment synthesis in the insect eye and mutations in these genes are used as genetic markers. Recent studies have suggested that these transporters also have additional functions in the neuronal system. In our previous study, we generated scarlet mutant in the small crustacean, Daphnia magna and showed that the mutant lacked the eye pigment in the mutant. Here, we show that the scarlet mutant exhibits spinning behavior. This phenotype is partly associated with the presence of light. Metabolomic analysis of a juvenile mutant revealed that the scarlet mutant has approximately one-tenth of the histamine content of the wild type. Application of histamine to the scarlet mutant rescued the spinning behavior in juveniles, suggesting that the spinning behavior of the mutant is caused by the reduction of histamine. However, the altered behavior was not rescued in the adult mutant by the addition of histamine, suggesting that Scarlet plays an irreversible role in the development of histaminergic neurons. These results suggest that Scarlet plays an important role in histaminergic signaling, which might be related to control the spinning behavior, in addition to its role in eye pigmentation.

Chemotaxis behaviour of Steinernema carpocapsae in response to Galleria mellonella (L.) larvae infected by con- or hetero-specific entomopathogenic nematodes

ABSTRACT Entomopathogenic nematodes (EPNs) infect insects and reproduce within the host cadaver. The nematodes use chemotaxis to assist in host-finding. However, the chemotaxis of nematode species in response to insects previously infected by con- and hetero-specific EPN in a sand context has rarely been reported. Our aim was to address the response of Steinernema carpocapsae All (Sc) to Galleria mellonella cadavers infected by con- or hetero-specific EPNs (Heterorhabditis bacteriophora HB1, S. feltiae SN, S. rarum 17 C&E) in sand via chemotaxis assays. Additionally, the effect of different time points post-infection was also evaluated. Results indicated that previously infected G. mellonella larvae repelled infective juveniles (IJs) of Sc (p < 0.05) regardless of the time point post-infection and EPN species (con- or hetero-specific) and had a lower chemotaxis index as compared to that of no larvae addition in both sides. Moreover, it was found that for each of four tested EPN species, EPNs infected insect cadavers released dimethyl disulphide, which was identified by solid-phase microextraction (SPME) coupled to gas chromatography–mass spectrometry (GC–MS). We found that dimethyl disulphide acted as a repellent to Sc infective juveniles and reached a significant effect at the level of 0.106 mol/L. Our findings could provide a better understanding of movement behaviour of EPN infective juveniles in response to insect resources in the presence of con- or hetero-specific EPNs.

Byssal re‐attachment behavior in the winged pearl oyster Pteria penguin in response to low salinity levels

AbstractThe effect of low salinity levels on byssal re‐attachment behavior in Pteria penguin juveniles was observed in the laboratory. Juvenile pearl oysters were submerged in seawater blended to 8.0, 12.0, 16.0, 20.0, 24.0, 28.0, and 32.0 salinity levels for a period of 48 hr. The sub‐lethal salinity level was greater than 20.0 psu. Although salinity levels of 20.0 and 24.0 psu did not affect the oyster survival, the observed byssogenesis activity was significantly reduced and locomotion activity was delayed. Description of the effects of low salinity levels on the byssal re‐attachment behavior of P. penguin juveniles provides a foundation for the design of more complex experiments and approaches to further the exploration and development of improved pearl production techniques.

Chronological and regional variation in developmental stress and behavior of Early and Late Neolithic Cis-Baikal hunter-gatherer juveniles: Insights from diaphyseal cross-sectional geometry

This study explores growth (increase in size) and development (change in structure and function) in Middle Holocene Cis-Baikal hunter-gatherer populations to evaluate chronological and regional variation in developmental health and juvenile behavior using post-cranial Cross-Sectional Geometry (CSG). It also evaluates whether sexual differences in size and habitual behavior were evident by the end of adolescence. Age and body size standardized femur, tibia, and humerus midshaft CSG are used to test for differences between Early Neolithic (EN) and Late Neolithic (LN) juveniles from different micro-regions. Regression of these measures on radiocarbon date tests for differences within archaeological periods.EN individuals younger than 16 years, particularly those from the Angara River Valley, exhibit lower measures of cross-sectional size/ rigidity than LN juveniles. EN individuals older than 6 years, especially those from the Southwest Baikal had less circular lower limbs and higher humerus percent cortical area than LN individuals. Age standardized cross sectional size/ rigidity decline throughout both the EN and the LN, suggesting decrease in body size during both archaeological periods, whereas changes in femur shape are consistent with increases in juvenile mobility throughout the EN. By the end of adolescence, sexual dimorphism is emerging but not fully established in lower and upper limb robusticity and shape.The lower cross-sectional area and bending rigidity support higher levels of developmental stress in the EN compared to the LN period, whereas less circular lower limb indices suggest higher terrestrial mobility in the EN. These differences may reflect may a higher risk of resource scarcity in the EN, which resulted in higher mobility and greater involvement of juveniles in harvesting aquatic resources. Declines in body size within both archaeological periods emphasize the cyclical nature of developmental stress, perhaps due to declines in resource abundance. The presence of incipient sexual dimorphism by the end of adolescence is consistent with individuals beginning to assume adult roles.

Adaptive differentiation of growth, energetics and behaviour between piscivore and insectivore juvenile rainbow trout along the Pace-of-Life continuum.

Adaptive trade-offs are fundamental mechanisms underlying phenotypic diversity, but the presence of generalizable patterns in multivariate adaptation and their mapping onto environmental gradients remain unclear. To understand how life history affects multivariate trait associations, we examined relationships among growth, metabolism, anatomy and behaviour in rainbow trout juveniles from piscivore versus insectivore ecotypes along an experimental gradient of food availability. We hypothesized that (a) selection for larger size in piscivorous adults would select for higher juvenile growth at the cost of lower active metabolism; (b) elevated growth of piscivores would be supported by a greater productivity of their natal stream and more proactive foraging behaviours and (c) general patterns of multivariate trait associations would match the predictions of the Pace-Of-Life Syndrome. Relative to insectivores, piscivorous fry showed a pattern of higher growth (+63%), maximum food intake (+33%), growth efficiency (+41%) and standard metabolic rate (SMR; +47%), but lower active metabolic capacity (maximum metabolic rate [MMR; -17%], aerobic scope [AS; -48%]), suggesting that faster piscivore growth is supported by greater food intake and digestive capacity but is traded-off against lower scope for active metabolism. A similar trade-off appeared among organ systems, with piscivorous fry exhibiting an 83% greater investment in average mass of organs associated with food consumption and processing (i.e. stomach and intestine), but an apparently smaller relative investment in organs involved in cardiovascular or cognitive activities (heart and brain, respectively). Higher invertebrate drift in their natal rearing habitat, quicker behavioural transition to a novel food source and lower anxiety after a frightening event in piscivorous fry suggest that faster growth requires both proactive foraging behaviours and higher prey availability in the environment. Finally, the sampling of replicate insectivore populations confirmed their lower juvenile growth (-73% on average) and reduced environmental productivity of their natal streams (-45% lower drift abundance) relative to the piscivore ecotype. Our results suggest that selection for large adult body size influences selection on high juvenile growth, high basal metabolism and proactive behaviours, and that the intense phenotypic divergence between piscivorous and insectivorous rainbow trout may be constrained by environmental productivity.

Relative Influence of Environmental Factors on Biodiversity and Behavioural Traits of a Rare Mesopelagic Fish, Trachipterus trachypterus (Gmelin, 1789), in a Continental Shelf Front of the Mediterranean Sea

Coastal environments can be influenced by water body masses with particular physical, chemical, and biological properties that create favourable conditions for the development of unique planktonic communities. In this study, we investigated a continental shelf front at Ponza Island (Tyrrhenian Sea) and discussed its diversity and complexity in relation to major environmental parameters. Moon phase and current direction were found to play a significant role in shaping species abundance and behaviour. During in situ observations, we also provided the first data on the behaviour of juveniles of a rare mesopelagic species, Trachipterus trachypterus, suggesting the occurrence of Batesian mimicry.

Use of the sea urchin Diadema antillarum (Echinodermata, Echinoidea) as a shelter for non-cryptobenthic juvenile reef fishes

Marine species can act as biogenic sources of habitat structures, increasing the web of interactions between reef fishes and the benthic environment. Among these species, sea urchins seem to play an ecological role that goes beyond the dynamics of coral-algal interaction on reef ecosystems. In this paper, we describe the commensal behavior of juveniles of two non-cryptobenthic reef fishes (Haemulon parra and Abudefduf saxatilis) with the sea urchin Diadema antillarum on sandstone reefs in Northeastern Brazil. Behavioral observations in situ raise the assumption that D. antillarum may provide an alternative source of shelter and therefore influence microhabitat complexity, particularly, for juvenile reef fishes.

EFFECT OF ILLUMINATION ON GROWTH AND BEHAVIOUR OF GUPPY, POECILIA RETICULATA

The guppy, Poecilia reticulata, is a model for many ichthyological studies. The effect of light on juvenile growth has been studied on the Poecilia reticulata. Studies have been conducted in twenty-liter aquariums. For experiments on the fish arbitrary choice of light intensity (light transmission behavior), it was used radiant pans of organic glass 150 x 15 x 15 cm divided by transparent semi-partitions into ten communicating compartments. The specific growth rate has been determined after the experiments. It increases with the light level increasing. The growth rate is minimal at 0 lx in all series of experiments. It was shown that the sharpest increase in the specific growth rate of guppies occurred when the illumination changed from 0 to 200 lx. A further increase in the intensity of illumination practically did not affect the growth of guppies. Also, the guppy juvenile behavior has been studied in special trays at different light from 3200 to 5900 lx. The motor activity of guppies increases by 30% in lightgradient conditions. The frequency (25 sec) and length of guppies stay (28.3 sec) are the highest in the compartment with 4700 lx. The preferential light zone expands if the juveniles are starving. As the period of starvation increased, guppies began to swim almost equally often and linger in different light zones. Thus, high light conditions stimulate the search behavior and activity of guppies. To grow guppies in production conditions, high illumination is necessary.

Influence of past and current social contexts on hunting behaviour in spiderlings

When foraging in a group, individuals adjust their behaviours to the actions of others in order to optimize their pay-offs. While many studies have examined the influence of group composition on behavioural strategies, relatively few have investigated how the presence or absence of conspecifics influences the expression of behaviours during hunting. Another aspect that has received little attention concerns the impact of prior social experience on the expression of predatory behaviour. Here, we studied how past and present social contexts influenced predatory behaviour in juveniles of the spider Agelena labyrinthica which, like most solitary species, exhibit a transient gregarious phase prior to dispersal. We tested, alone or in pairs, spiderlings that have been maintained in isolation or in groups for 24 h prior to behavioural assays. During the tests, we introduced a live prey to an experimental arena and we measured the latencies associated with the different phases of the hunting sequence. We found that spiders maintained in isolation captured prey faster than those kept in groups and that the presence of a sibling increased the latency of prey capture compared with individuals hunting alone. Such a social context effect adds another dimension to the already complex combination of factors that determine the success of spider foraging. Overall, our study reveals an influence of the social dimension, past and present, on hunting behaviour that may have been underestimated in carnivores. It is generally considered that hunting in group increases individual benefits compared with solitary hunting. However, relatively few studies have compared hunting performance between individuals hunting alone or in group to assess how the presence of conspecifics impacts the expression of predatory behaviours. Another aspect that has been little explored concerns the role of the social context previously experienced on hunting behaviour. This study examined the influence of past or present social context on hunting behaviour in juveniles of a solitary spider during their gregarious phase. We showed that spiderlings maintained in isolation or tested alone were faster at catching prey than congeners reared socially or tested in groups. This study highlights a cost to sociality that has so far received little attention, and which could be an important element to consider in understanding transitions to permanent sociality.

HALANGAN DALAM RESOSIALISASI: SATU ANALISIS DARI KONTEKS MALAYSIA

The process of resocialization is important to ensure that juveniles at the rehabilitation institution changed as expected by the community. But the process of resocialization will not completely successful if there are barriers. Therefore, the aim of this study is to identify barriers that derange the successful resocialization process of juveniles. The data were obtained through an in-depth interview session with the respondent in the study and observation. Through purposive sampling, the twenty-seven staff of a correctional institution and twenty-three juveniles were selected to participate as respondents in this study. This study revealed that there were barriers that deranged the resocialization process such as juveniles factor (juvenile behavior; not interested in learning, religion classes, activities, programs), rehabilitation institution’s factor (inadequate facilities, inadequate finance), juvenile family’s factor (socioeconomic of the family, lack of parents’ responsibility) and society factor (negative perception of society). In conclusion, these findings prove that there are obstacles in order to resocialize juveniles from the Malaysian context. If these obstacles are not well addressed, it will give a negative impact not only on juveniles but also on Malaysia.

The influence of size on the trophic interactions between juveniles of two syntopic Trachinotus species

AbstractSyntopic species with similar anatomic configuration may face strong competition for trophic resources, thus relying on developed mechanisms to ensure coexistence. The present study investigated the influence of body size on trophic interactions between juveniles of two closely related fish species at three sandy beaches in south-eastern Brazil. A total of 150 fish were sampled, where 103 were identified as Trachinotus carolinus (mean ± SE: weight = 9 g ± 1.13) and 47 as Trachinotus goodei (weight = 46.7 g ± 3.34). A significant size-difference between juvenile Trachinotus was detected by a null-model analysis (P = 0.04), with T. carolinus (TL = 79.6 mm ± 2.4) presenting a smaller body size than T. goodei (TL = 147.7 mm ± 4.2). The main prey items consumed by T. carolinus were Perna perna (IAi = 0.76) and Emerita brasiliensis (IAi = 0.18), whereas the latter was the major T. goodei dietary prey (IAi = 0.71). Both prey were correlated with larger-sized juveniles of each pompano species, whereas smaller fish shared non-preferred trophic items. Such opportunistic behaviour of smaller juveniles may account for the dietary overlap detected between the Trachinotus species (P = 0.09). Size-related dietary partitioning was observed for the largest T. goodei juveniles, which displayed only a slight overlap with T. carolinus, and between juveniles belonging to the small and medium size groups of each pompano species. Therefore, food partitioning related to pompano body size seems to be especially important for the smallest juveniles, as they present the highest vacuity (particularly T. carolinus) in the sampled beaches, suggesting that these individuals are under intra- and interspecific competitive pressure, which may affect local coexistence.

Anomalous moral intuitions in juvenile offenders with psychopathic traits

Since the historical conception of psychopathy, researchers have been interested in understanding moral functioning among psychopathic individuals. The present study investigated the association between psychopathic traits and moral intuitions among incarcerated juvenile offenders (N = 178). Participants were assessed using the Psychopathy Checklist:Youth Version (Forth, Kosson, & Hare, 2003) and the Moral Foundations Questionnaire (Graham et al., 2011), which defines five core moral foundations: Harm/care, Fairness/reciprocity, Ingroup/loyalty, Authority/respect, and Purity/sanctity. As expected, psychopathy in juvenile offenders negatively predicted endorsement of all five foundations. This study is the first to demonstrate broad abnormalities in Haidt et al.’s moral foundations in a juvenile sample and can help explain delinquent behavior in juveniles with psychopathic traits. Implications for theories of psychopathy are discussed.

Социологический анализ подростковой делинквентности в контексте социальных институтов: по материалам социологического исследования

The paper presents the analysis of adolescent delinquency in the context of social institutions, prepared basing on the materials of sociological research. The authors conduct a detailed analysis of the contents of the notion “delinquency”. Particular attention is paid to the evaluation of the role of delinquent behavior in modern society, the relationship of this social phenomenon with the activities of various social institutions – subjects of social control. Ways to improve social control for the prevention of delinquency of juveniles are considered. The work presents the results of a sociological study aimed at studying the problem of the delinquent behavior of juveniles in the context of social institutions, conducted with the help of a questionnaire survey of teachers and students of grades 7-11 and expert surveys. Data on the prevalence of delinquent behavior of juveniles are given. The main areas of solving the problems of prevention of offences by juveniles have been highlighted.

Family Disadvantages as a Factor of Development of Deviant Behaviour of Juveniles

The article covers the problem of deviant behaviour of juveniles brought up in dysfunctional families. The aim of this work is to identify the correlation of family disadvantages and deviant behaviour of children and adolescents. The risk factors of social maladaptation of children, the specifi cs of family disadvantages are studied. An innovative method of socio-pedagogical work with preschool children and their parents is proposed in order to prevent the development of antisocial behaviour.

Effects of salinity on survival and plasma osmolarity of Totoaba macdonaldi eggs, larvae, and juveniles

Totoaba macdonaldi, an endemic fish from the Gulf of California, is currently considered an endangered species by the Mexican Federal Government since its bladder is a high-priced item in China's black market. Totoaba is considered the cause of extinction of the marine porpoise vaquita marina (Phocoena sinus) due to Illegal fishing. It inhabits the Colorado Delta River Marine Reserve, an area with very high productivity, biomass, species endemism, and a marine nursery.To explore its osmoregulatory capabilities, totoaba specimens were exposed to different salinity conditions (from 5 to 40 psu) under laboratory trials. Several developmental stages were tested (eggs, larvae, and juveniles), from which blood and water osmotic pressure (OP), survival, water and total ash content were evaluated, confirming the euryhaline behavior of juveniles. However, larval stages were very dependent on external media salinity concentration. The responses to salinity acclimation and shifts in survival recorded were closely related to its migratory strategy, which can have important ecological consequences.

The Qualitative Analysis of Psychosocial Profile of Juvenile Offenders and Exploration of Their Perception towards Delinquent Behaviors

Juvenile delinquency or juvenile offending generally means the failure of children to meet certain obligations expected of them by the society. The study aimed for qualitative analysis of psychosocial factors which played a crucial role in exhibiting the delinquent behavior of juveniles and also explored the perception towards their offences. Cross sectional research design was used and thirty juveniles within the age range of 10-17 years involved in delinquent activities were selected by the use of purposive sampling method. Out of 30 juveniles, fifteen of them had committed heinous crimes like rape and murder and the remaining fifteen juveniles had committed non-heinous offenses like burglary, theft, kidnapping, physical assault and cybercrime. The qualitative analysis found many factors like poor tolerance level, anger management and school performance, media influence, low socio-economic status, presence of illness in the family and crime in neighborhood as risks for juvenile delinquency. It was also noticed that juvenile offenders had poor sense of responsibility, understanding or comprehension and awareness related to the delinquent act. Majority of them attributed their delinquent act to the external factors and denied having any positive feelings towards the victim. The exploration of risk factors and offenders understanding and perception toward crime would help in prevention and intervention programs. Implication and limitations of the study were discussed.

Homelessness and neglect: on the nature of the phenomena and the correlation between legal terms

The authors of the article carry out the normative and doctrinal analysis of the terms &amp;ldquo;homelessness&amp;rdquo; and &amp;ldquo;neglect&amp;rdquo;, and identify the reasons and conditions of these antisocial phenomena in Russian society.&amp;nbsp; The research object is the legal and pedagogical aspects of the process of prevention of neglect and homelessness of minors and the activities of public authorities both in Russia and abroad. The research subject is the terms &amp;ldquo;homelessness&amp;rdquo; and &amp;ldquo;neglect&amp;rdquo; as legal terms. Special attention is given to the reasons of homelessness and neglect of juveniles, in the first place, biological and social orphanage. The research is based on the dialectical, formal-logical (dogmatical), historical-legal, systems, linguistic and some other methods of scientific cognition. The priority methods were the sociological and formal-legal methods and the method of comparative jurisprudence. The scientific novelty of the research consists in the fact that based on the analysis of legal and essential roots of the two phenomena, the authors conclude that despite being formalized, they require fundamental review of the approaches to study and identification. It is necessary to transform the understanding of the model of juvenile behaviour which is connected with the recently changed basic scientific approaches in pedagogical psychology and social pedagogics. Taking into account the size of the problem of orphanage, the authors suggest aiming public social politics not only at the protection of rights of orphans and their adoption, but also at avoiding the cases of deprivation of parental care. The most active instrument in this context is the prevention of social orphanage by the child protection services which includes pedagogical, psychological, legal, social, educational and medical assistance to families with and without family disadvantages risk factors.&amp;nbsp; &amp;nbsp;