Juvenile Females Research Articles

Productivity of superovulated C57BL/6J oocyte donors at different ages.

Superovulation is often used to increase the number of oocytes that can be collected from donor females for in vitro fertilization. Donor age can affect the quantity and quality of oocytes produced during superovulation, and in some strains of mice juvenile females are optimal donors. The authors reviewed donor and oocyte records from a breeding program to evaluate how donor age affects the number and fertilization efficiency of oocytes collected from C57BL/6J mice. Generally fewer oocytes per donor were collected from females aged > 32 d than from females aged 21-32 d. Fertilization efficiency of oocytes generally declined with donor age when oocytes were fertilized with fresh or with stored sperm. These findings suggest that the use of younger C57BL/6J donors, instead of older donors, can reduce the number of donors needed for IVF procedures.

Female Juvenile Sexual Offenders: Understanding Who They Are and Possible Steps That May Prevent Some Girls From Offending

In recent years, there has been accumulating evidence that sexual abuse committed by females is not rare and can be just as traumatic as sexual abuse committed by males. Despite the increased recognition given to sex offending by adult women, however, very little attention has been given to sex offenses committed by juvenile females. There has further been very little published material that has focused specifically on intervening with female children and adolescents before they offend. In an attempt to fill this gap, this article describes common characteristics of juvenile female sex offenders, ways in which juvenile female sex offenders are similar to and different from juvenile male sex offenders, and the limitations that exist related to our knowledge about these offenders. Based on this information, suggestions are given for possible ways to intervene in the lives of at-risk female youth before they offend.

Cognitive Impairment After Sleep Deprivation Rescued by Transcranial Magnetic Stimulation Application in Octodon degus.

Sleep is indispensable for maintaining regular daily life activities and is of fundamental physiological importance for cognitive performance. Sleep deprivation (SD) may affect learning capacity and the ability to form new memories, particularly with regard to hippocampus-dependent tasks. Transcranial magnetic stimulation (TMS) is a non-invasive procedure of electromagnetic induction that generates electric currents, activating nearby nerve cells in the stimulated cortical area. Several studies have looked into the potential therapeutic use of TMS. The present study was designed to evaluate how TMS could improve learning and memory functions following SD in Octodon degus. Thirty juvenile (18 months old) females were divided into three groups (control, acute, and chronic TMS treatment-with and without SD). TMS-treated groups were placed in plastic cylindrical cages designed to keep them immobile, while receiving head magnetic stimulation. SD was achieved by gently handling the animals to keep them awake during the night. Behavioral tests included radial arm maze (RAM), Barnes maze (BM), and novel object recognition. When TMS treatment was applied over several days, there was significant improvement of cognitive performance after SD, with no side effects. A single TMS session reduced the number of errors for the RAM test and improved latency and reduced errors for the BM test, which both evaluate spatial memory. Moreover, chronic TMS treatment brings about a significant improvement in both spatial and working memories.

Effect of the exoskeleton micro-damages on molting of juvenile red king crab in the Barents Sea

Effect of multiple small body damages on molting of red king crab is studied in laboratory conditions. Both male and female juveniles of red king crab with the carapace width 80-100 mm were used in the experiments. After removing of all spines from limbs and carapaces, mean duration of intermolt periods decreased significantly: the crabs without spines molted in 40-45 days earlier than intact ones. The effect of molting induction by spines removing was weaker than the induction by alternative methods but had no negative consequences as heightened mortality or limb autotomy. This procedure could be used for stimulation of molting in artificial conditions.

Patterns of ectoparasitism in North American red squirrels (Tamiasciurus hudsonicus): Sex-biases, seasonality, age, and effects on male body condition.

Within many species, males are often more heavily parasitised than females. Several hypotheses have been proposed to explain this phenomenon, including immunocompetence handicaps, sexual size dimorphism and behavioural differences. Here we set out to test the latter two hypotheses and make inferences about the former by assessing patterns of ectoparasitism across various life-history stages in a population of North American red squirrels (Tamiasciurus hudsonicus). We also conducted an ectoparasite removal experiment to investigate the effects of ectoparasites on male body condition. We found that males were more intensely parasitized than females, but only during the mating period. There was no difference in ectoparasite intensity between male and female juveniles at birth or at emergence, suggesting that ectoparasites do not exploit male red squirrels for longer-range natal dispersal. Male red squirrels in our population were slightly heavier than females, however we did not find any evidence that this dimorphism drives male-biased ectoparasitism. Finally, we could not detect an effect of ectoparasite removal on male body mass. Our results lend support to the hypothesis that ectoparasites exploit their male hosts for transmission and that male red squirrels are important for the transmission dynamics of ectoparasites in this population; however, the mechanisms (i.e., immunocompetence, testosterone) are not known.

Female Juvenile Violent Behavior: Bonding Systems and Other Mediating Constructs

The purpose of this research was to examine a conceptual/theoretical model with negative (substance use) and positive (extracurricular activities) mediating factors between several bonding systems and violent behavior among female youth. Since much of the prior researches have focused on both males and females therefore this study is focusing on females only. Data from the 2011 National Survey on Drug Use and Health was used for this study. For the purpose of this study female research participants between the age of 12–17 were selected (N = 9383). At the stage of bivariate analysis, parental bonding system was omitted from a model before moving onto a structural equation modeling (SEM) analysis as most of the correlations between indicators of parental bonding systems and dependent variables were not significant. Revised model with two bonding systems on violent behavior through two mediating constructs, extracurricular activities and substance use were tested through the SEM and Sobel test analyses. This structural model specifies a satisfactory fit with the sample. Several mediating effects within this model, which help lower the occurrence of violent behavior, were also validated.

Endoparasite infection has both short- and long-term negative effects on reproductive success of female house sparrows, as revealed by faecal parasitic egg counts.

Parasites have the potential to severely reduce host reproductive success. However, the effects of endoparasites on reproductive success have not received the same amount of attention as the effects of parasites on host survival. We investigated the relationship between an avian endoparasite (gapeworm, Syngamus trachea) and both current and future reproductive success of female house sparrows (Passer domesticus) in a population on the coast of Helgeland, northern Norway. We found that the proportion of eggs in a nest that failed to develop into fledglings increased as the faecal parasitic egg count of the mothers increased. We also found that juvenile females with high numbers of parasitic eggs in their faeces had lower lifetime reproductive success as adults. However, we did not find a relationship between maternal parasite infection and clutch size or recruitment rate of offspring. To our knowledge this is the first study to find a relationship between reproductive success of an avian host and faecal egg count of an endoparasite. The present study indicates that infection by an endoparasite may be associated with lower individual reproductive success in both the short-term and long-term in a wild population of hosts.

Body language: The interplay between positional behavior and gestural signaling in the genus Pan and its implications for language evolution.

The gestural repertoires of bonobos and chimpanzees are well documented, but the relationship between gestural signaling and positional behavior (i.e., body postures and locomotion) has yet to be explored. Given that one theory for language evolution attributes the emergence of increased gestural communication to habitual bipedality, this relationship is important to investigate. In this study, we examined the interplay between gestures, body postures, and locomotion in four captive groups of bonobos and chimpanzees using ad libitum and focal video data. We recorded 43 distinct manual (involving upper limbs and/or hands) and bodily (involving postures, locomotion, head, lower limbs, or feet) gestures. In both species, actors used manual and bodily gestures significantly more when recipients were attentive to them, suggesting these movements are intentionally communicative. Adults of both species spent less than 1.0% of their observation time in bipedal postures or locomotion, yet 14.0% of all bonobo gestures and 14.7% of all chimpanzee gestures were produced when subjects were engaged in bipedal postures or locomotion. Among both bonobo groups and one chimpanzee group, these were mainly manual gestures produced by infants and juvenile females. Among the other chimpanzee group, however, these were mainly bodily gestures produced by adult males in which bipedal posture and locomotion were incorporated into communicative displays. Overall, our findings reveal that bipedality did not prompt an increase in manual gesturing in these study groups. Rather, body postures and locomotion are intimately tied to many gestures and certain modes of locomotion can be used as gestures themselves.

Patterns of survival and roost switching in an African insectivorous bat

AbstractVariation in survival over time and among age and sex classes drives population dynamics for a large majority of long‐lived species and is critical to understanding species demography. For highly mobile species that actively move among potential breeding locations, coupling survival information with estimates of locational fidelity provides the basis for our understanding of species population dynamics. We studied the effect of time, age and sex class and climatic variables on survival and roost transition probabilities on a population of Egyptian slit‐faced bats in Swaziland from 1450 marked individuals from 16 roosts over a 10‐year period. We then used variance components analysis to estimate average annual survival and associated temporal process variance. Annual apparent survival varied with sex and age, being highest in adult males and lowest in juvenile females. We did not find evidence of survival being influenced by climatological factors as commonly observed in temperate bats. Roost switching occurred frequently, with more transitions to roosts harboring larger number of bats. Furthermore, the probability of transitioning to another roost was related to its distance from the original roost. The dispersal patterns revealed in this study were consistent with the fission–fusion dynamics common for colonial bats.

Extinction and reinstatement to cocaine-associated cues in male and female juvenile rats and the role of D1 dopamine receptor

Extinction of behaviors in response to drug-associated cues and prevention of reinstatement are integral for addiction treatment, and can reverse or ameliorate the harmful consequences of drug use. The mechanisms controlling extinction and reinstatement involve prefrontal cortical dopamine receptors, which change in expression and activity during the juvenile and adolescent transitions until they mature in adulthood. Little is known about the role that PFC D1 dopamine receptors play in extinction of drug-paired associations early in life. We used extinction of place preferences for cocaine in juvenile male and female rats following genetic, cell-specific overexpression of D1 on glutamatergic cells in the PFC. All subjects needed to demonstrate cocaine preferences for inclusion in the extinction studies. Here, male juveniles with a preference to 10 mg/kg cocaine took longer to extinguish preferences compared to both male adults and female juveniles. Female juveniles extinguished more rapidly than male juveniles at 20 mg/kg cocaine. Overexpression of D1 in juvenile males significantly facilitated extinction relative to juvenile male controls, whereas D1 prolonged expression of extinction in adults overexpressing D1 and adolescents who naturally have elevated D1 expression. These data suggest that an immature D1 profile in juveniles prevented the learning of new associations, and D1 overexpression may provide sufficient activity to facilitate extinction learning. D1 overexpression reduced reinstatement to a priming dose of cocaine in juvenile males. Together, these data show D1 expression may re-program motivational circuitry to facilitate extinction learning during juvenility that is normally unavailable to juveniles and that sex differences exist.

Brain serotonin deficiency leads to social communication deficits in mice.

A deficit in brain serotonin is thought to be associated with deteriorated stress coping behaviour, affective disorders and exaggerated violence. We challenged this hypothesis in mice with a brain-specific serotonin depletion caused by a tryptophan hydroxylase 2 (TPH2) deficiency. We tested TPH2-deficient (Tph2(-/-)) animals in two social situations. As juveniles, Tph2(-/-) mice displayed reduced social contacts, whereas ultrasonic vocalizations (USVs) were unchanged within same-sex same-genotype pairings. Interestingly, juvenile females vocalized more than males across genotypes. Sexually naive adult males were exposed to fresh male or female urine, followed by an interaction with a conspecific, and re-exposed to urine. Although Tph2(-/-) mice showed normal sexual preference, they were hyper-aggressive towards their interaction partners and did not vocalize in response to sexual cues. These results highlight that central serotonin is essential for prosocial behaviour, especially USV production in adulthood, but not for sexual preference.

Nonmaternal Infant Handling in Wild White-Headed Langurs (Trachypithecus leucocephalus)

Infants of many primate species have extensive interactions with group members other than their mothers, which can affect an infant’s fitness. Patterns of nonmaternal infant handling vary according to the mother’s response as well as the number, sex, age, and dominance ranks of social partners. The primary goal of this study was to identify the basic pattern and explore the function of nonmaternal infant handling behavior in wild white-headed langurs (Trachypithecus leucocephalus) at the Nongguan Hills in Guangxi, Southwest China. We report nonmaternal interactions in the first 3 mo after birth for 15 infants born during six birth seasons in a 67-mo field study. The nonmaternal infant handling we observed was generally in the form of caregiving, and mothers permitted most handling attempts. Infants were handled by nonmothers from the first day after birth. Infants spent 20–30% of the daytime associated with nonmothers during the first month of life, and time in contact with nonmothers decreased with infant age. Rates of nonmaternal infant handling varied significantly with the sex and age of handlers. Juvenile and subadult females handled infants significantly more than expected from their proportional representations in the group, whereas adult females did so less frequently than expected. Older male infants and juvenile males rarely handled infants, and adult males never did so. Infant handling behavior showed no correlation with the dominance rank of handlers relative to the mothers. Our data, although limited in some analyses, are in line with the predictions of the learning-to-mother hypothesis, but do not support the female competition or alliance formation hypotheses.

Daughters are more strongly attached to their mother than sons: a possible mechanism for early social segregation

Social factors hypotheses predict that social segregation between male and female adult ungulates is due to social preferences among same-sex peers and avoidance of the opposite sex, rather than aggregation due to body size dimorphism and differential needs of the sexes. It is suggested that if such social preference/avoidance exists its roots should be early in life. While juvenile ungulate males show social preference for same-sex and same-age peers a few weeks after birth, no studies have confirmed such a phenomenon in juvenile females. In this study we investigated another possible mechanism that would result in an early social preference for same-sex conspecifics among juvenile females: we hypothesized that offspring–mother attachment is stronger for daughters than for sons. Attachment was measured in lambs, Ovis aries, using three characteristics defined initially in children: proximity seeking, distress following separation and exploration in the mother's presence. Lambs were tested at 3 weeks of age in two experimental situations in which they could interact with the mother, a familiar ewe or an unfamiliar ewe. (1) During a choice test between the mother and the familiar ewe, daughters maintained closer proximity with the mother than sons did. During the test without the mother (a familiar versus an unfamiliar ewe) daughters were more distressed than sons were. (2) In an isolation–reunion–separation test, reunion with the mother increased exploratory behaviour more in daughters than in sons. Overall, our results reveal that daughters displayed stronger attachment behaviours and could be more strongly attached to their mother than sons are. Such early preference may be a key factor leading to social preference among females and social segregation between the sexes.

Re-description of the slug-parasitic nematode Alloionema appendiculatum Schneider, 1859 (Rhabditida: Alloionematidae)

Alloionema appendiculatum is a common juvenile parasite of many terrestrial molluscs. Its third-stage juveniles (dauers) invade the foot muscle of snails and slugs and develop into fourth-stage juveniles, which then leave the host. Later they mature and reproduce in the soil. A population of A. appendiculatum was isolated from infected individuals of the invasive slug Arion vulgaris (= A. lusitanicus), collected in the city of České Budějovice, Czech Republic, and was designated as the AL strain. This nematode is also able to reproduce on pig kidney in laboratory culture. Our isolate was compared primarily with the description published by Mengert (1953) and in some aspects with the original description published by Schneider (1859). Insufficient morphology, morphometrics, phylogeny and an absence of pictorial material encouraged us to re-describe this frequent slug parasite and to add some new information on its life-cycle. The species is characterised by the absence, in adults, of ridges in the lateral fields. At this life stage the stoma is short, narrow and approximately twice as long as it is broad. Fourth-stage female juveniles produce a mucus-like substance from the phasmids. Males possess six pairs of papillae and a single inconspicuous papilla. The nematode has both parasitic and saprophytic life-cycles. Parasitic adults are bigger than the saprophytes and have a thick, digitate tail, whereas the smaller saprophytic generation has a filiform tail. The species is amphimictic, displaying a higher proportion of females, but males are frequent.

Investigation of Pathways to Delinquency: Exploring Associations between Familial Background, Traumatic Victimization and Violent Behavior among Urban Female Adolescents

Investigation of Pathways to Delinquency: Exploring Associations between Familial Background, Traumatic Victimization and Violent Behavior among Urban Female Adolescents Dr. Zina T. McGee, Raine K. Cunningham, Ayana K. Churn, La Shawndra Hooks, Shaqwanda W. Everett, Nicollette Strickland, Tamara Dobson-Brown, MyKeya Foreman Abstract This paper discusses parental background and traumatic victimization as risk factors for violent delinquency among a sample of 208 urban adolescent females. Focus group and in-depth interviews conducted on a subsample of 20 participants are also presented, and emphasis is placed on the factors that place these female juveniles at a greater risk of engaging in delinquent behavior. Suggestions for future research are also addressed. Full Text: PDF DOI: 10.15640/ijgws.v3n1a2

The Centrality of Gender to Understanding Turkish Politics

The Centrality of Gender to Understanding Turkish Politics

Lived Experiences of Egyptian Female Juvenile Delinquents: Phenomenological Approach

Historically delinquency was considered the domain of boys, but recently female juvenile delinquents are a sizeable minority of the overall delinquent population, henceforth, current study aimed to explore the lived experiences of female juvenile delinquents in Egypt. A qualitative research approach was achieved by conducting focus group discussions with delinquent females and in-depth interviews with key workers from three residential correctional institutions in Egypt. Findings indicated that female juvenile delinquency is a multidimensional phenomenon resulting from stacking sets of strained relationships, community, & individual triggering factors. Ultimately the crux of female juvenile delinquency is the family.

Group sexual offending by juvenile females.

This study examined all group sexual offending cases in the Netherlands between 1995 and 2009 (n = 26) in which at least one juvenile female offender (n = 35) had been adjudicated. Information from court files showed that the majority of juvenile female group sexual offenders have (inter)personal problems and (sexual) abuse experiences. The aims of the offender groups in committing the offense could be categorized in three themes: harassing the victim, sexual gratification, and taking revenge. The reasons why juvenile female offenders participated in a group could be categorized into group dynamics versus instrumental reasons. The findings are contrasted with findings on juvenile male group sexual offenders. Implications of the findings for research and treatment are discussed.

Size-Based Mortality of Adult Female Diamond-Backed Terrapins (Malaclemys terrapin) in Blue Crab Traps in a Gulf of Mexico Population

Mortality incidental to trapping for blue crabs is a primary threat to diamond-backed terrapin (Malaclemys terrapin) populations. Due to sexual size dimorphism in this species, crab-trap mortality is believed to be biased toward smaller adult males and juvenile females. However, a comparison of commercial trap funnel openings and adult female size from a Gulf Coast population suggested that crab-trap mortality is a larger threat than previously thought to adult female terrapins in this population and possibly others.

Movement of satellite-tracked juvenile saker falcons (Falco cherrug) in SW Slovakia

Abstract During the period 2008-2011 nine juvenile saker falcon females from SW Slovakia were tracked with satellite telemetry. The movement of four of those females tagged with satellite tracking devices was analysed in 2011 (two juveniles for 6 months, one for 5 months and one for 3 months). The analysis of the collision risk with wind turbines also used telemetry data from previous years (2008-2009) - five birds tracked from abandoning their nest to abandoning their post-fledging areas (i.e. 45, 48, 37, 11 3 and 1 34 days). The juveniles visited 1 3 different countries during their post-fledging dispersal and migration. Maximum distance from the nest varied between 1 53 and 2094 km. For two birds the cause of death was recorded: one female was electrocuted and other female was probably also electrocuted. We also evaluated two factors of potential wind turbine threat: a) the distance ofGPS locations from the nearest wind turbines in the vicinity of post-fledging areas, b) numbers ofwind turbines in post-fledging areas. Assessment of the collision risk with wind turbines showed low risk for the tracked individuals. Two of four tracked birds were at medium risk (2-5 km) from wind turbines. The highest risk for the young falcons comes from wind turbines in neighbouring countries, where they are constructed near borders