Morphological and Mechanical Changes in Juvenile Red-Eared Slider Turtle (Trachemys Scripta Elegans) Shells During Ontogeny

Turtles experience numerous modifications in the morphological, physiological, and mechanical characteristics of their shells through ontogeny. Although a general picture is available of the nature of these modifications, few quantitative studies have been conducted on changes in turtle shell shape through ontogeny, and none on changes in strength or rigidity. This study investigates the morphological and mechanical changes that juvenile Trachemys scripta elegans undergo as they increase in size. Morphology and shell rigidity were quantified in a sample of 36 alcohol-preserved juvenile Trachemys scripta elegans. Morphometric information was used to create finite element models of all specimens. These models were used to assess the mechanical behavior of the shells under various loading conditions. Overall, we find that turtles experience complementary changes in size, shape, deformability, and relative strength as they grow. As turtles age their shells become larger, more elongate, relatively flatter, and more rigid. These changes are associated with decreases in relative (size independent) strength, even though the shells of larger turtles are stronger in an absolute sense. Decreased deformability is primarily due to changes in the size of the animals. Residual variation in deformability cannot be explained by changes in shell shape. This variation is more likely due to changes in the degree of connectedness of the skeletal elements in the turtle's shells, along with changes in the thickness and degree of mineralization of shell bone. We suggest that the mechanical implications of shell size, shape, and deformability may have a large impact on survivorship and development in members of this species as they mature. J. Morphol. 275:391-397, 2014. 2013 Wiley Periodicals, Inc. Copyright 2013 Wiley Periodicals, Inc.

Juvenile spring eruption: an outbreak report and systematic review of the literature

Juvenile spring eruption of the helices of the ears is a distinctive sun-induced condition appearing on the light-exposed skin of the ears, typically in boys and young men in early spring.

Family Anomie and Juvenile Deliquency in Post-Communist Romania

The sensitivity of crime rates to social, economic and political influences has long aroused the interest of sociologists who have attempted to explain what kind of relationships might be associated with variations in crime rates between different social groups at different times. The earliest views were put forward by Emil Durkheim, and while later writers have developed (R.K. Merton, L. Srole, A, K. Cohen, etc.) have developed some aspects of his ideas further, his basic ideas of the divorce of the individual from normative standards and the lack of social integration are still valid. Ms. Voicu-Minea looked at the theoretical background in detail but then limited it to a specific social group, the family, asking first why certain individual within vulnerable families and/or negative social influences commit offences while others do not. In modern times the family has undergone massive structural and functional changes. Its former economic function, which once endowed it with a great capacity for social inclusion, has generally vanished, while its formerly crucial role in children's education has been massively reduced. These changes, which are still not complete, can lead to dysfunction and in certain social contexts such as that in post-communist Romanian society, this risk of dysfunction is still greater as unfavourably social circumstances more easily affect such families. The number of cases of juvenile delinquency in Romania has increased sharply ever since the end of the communist system and in 1996 reached the level of 18,317 cases. The sample examined included 1012 juvenile delinquents aged between 14 and 18, taken from all areas of Bucharest. Over 80% of charges related to theft, with more serious offences being relatively rare. The children underwent a series of psychological tests, accompanied by a questionnaire relating to family situation. The results showed that juvenile delinquency in Romania is overwhelmingly male, with 91.8% of offences being committed by boys. Two thirds of the research group were under the age of 16 and only just over one third attended school, with over half having left school before the legal age. While the majority of subjects had a lower than average level of education, they did not always recognise this, with two thirds seeing their level of education as being as good as or better than average. Nearly half the children (43%) did not live with both natural parents and majority came from families with three or more children. This applied both to their original families and to the families in which they were living at the time of the survey. The overwhelming majority of families were living in or around Bucharest, but under one third originated from there. Almost 25% of parents were under-schooled and around one third were unqualified workers. At least 30% of families lived in inadequate accommodation and family incomes were generally low. Ms. Voicu-Minea does however point out that over half the minors from the sample saw their family income as satisfactory or even more than satisfactory. When factors such as bad relationships between parents, corporal punishment, alcohol consumption and criminal records of family members were taken into account, the picture was bleak, making it understandable why over 36% of subjects had run away from home at least once, and in many cases repeatedly and for longer periods. The overwhelming majority of offences (80.8%) were committed in groups of between 2 and 11 persons, usually "friends" but in about 10% of cases member's of the family. IQ tests put about 75% of the sample at slightly under average, the difference being too slight to account for the behaviour problems of the majority. Personality tests, however, showed a different picture. Over 70% of those tested manifested an acute need of tenderness and a similar number a high level of potential aggressiveness. Almost half of the minors expressed such feelings as intolerance or a desire for revenge, and Ms. Voicu-Minea found a clear weakness of the Self. Around half the sample expressed sentiments of abandonment, renunciation and solitude.

Vitrectomy for juvenile uveitis: prognostic factors for the long-term functional outcome

PURPOSE: This study evaluated the long-term effect of pars plana vitrectomy (PPV) in children and adolescents with chronic uveitis on visual function, anatomical outcome, and the requirement of systemic treatment. Further, predictive preoperative factors associated with a beneficial visual outcome were assessed. METHODS: Retrospective review of 29 eyes of 23 consecutive paediatric and juvenile patients below 20 years of age with chronic uveitis who underwent a PPV for visually significant opacities in 25 eyes, vitreous haemorrhage in three eyes, and retinal detachment in one eye. The clinical diagnosis was chronic intermediate uveitis in 22 eyes and retinal vasculitis of different origin in seven eyes. RESULTS: LogMAR visual acuity improved from an average of 0.91 to 0.33 (P<0.001). Cystoid macular oedema (CME) was significantly reduced in eight of 10 eyes postoperatively (P=0.021). In the multiple regression analysis, a low preoperative logMAR visual acuity and the presence of a CME had a negative influence on the final logMAR visual acuity. Furthermore, the appearance of chronic uveitis relapses was significantly reduced from 15 eyes before to seven eyes after surgery (P=0.042). CONCLUSIONS: PPV has a beneficial effect on the course and the complications of chronic uveitis in paediatric and juvenile patients with respect to the anatomical and visual outcome. Preoperative logMAR visual acuity and clinically significant CME were the most accurate predictors for the functional outcome.