| 1. |
- Black, Karen H., et al.
(författare)
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A New Species of the Basal "Kangaroo'' Balbaroo and a Re-Evaluation of Stem Macropodiform Interrelationships
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11, s. e112705-
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Tidskriftsartikel (refereegranskat)abstract
- Exceptionally well-preserved skulls and postcranial elements of a new species of the plesiomorphic stem macropodiform Balbaroo have been recovered from middle Miocene freshwater limestone deposits in the Riversleigh World Heritage Area of northwestern Queensland, Australia. This constitutes the richest intraspecific sample for any currently known basal "kangaroo'', and, along with additional material referred to Balbaroo fangaroo, provides new insights into structural variability within the most prolific archaic macropodiform clade - Balbaridae. Qualitative and metric evaluations of taxonomic boundaries demonstrate that the previously distinct species Nambaroo bullockensis is a junior synonym of B. camfieldensis. Furthermore, coupled Maximum Parsimony and Bayesian phylogenetic analyses reveal that our new Balbaroo remains represent the most derived member of the Balbaroo lineage, and are closely related to the middle Miocene B. camfieldensis, which like most named balbarid species is identifiable only from isolated jaws. The postcranial elements of Balbaroo concur with earlier finds of the stratigraphically oldest balbarid skeleton, Nambaroo gillespieae, and suggest that quadrupedal progression was a primary gait mode as opposed to bipedal saltation. All Balbaroo spp. have low-crowned bilophodont molars, which are typical for browsing herbivores inhabiting the densely forested environments envisaged for middle Miocene northeastern Australia.
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| 2. |
- Craig, Wendy, et al.
(författare)
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Social Media Use and Cyber-Bullying: A Cross-National Analysis of Young People in 42 Countries
- 2020
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Ingår i: Journal of Adolescent Health. - : ELSEVIER SCIENCE INC. - 1054-139X .- 1879-1972. ; 66:6, s. S100-S108
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Social media use (SMU) has become an intrinsic part of adolescent life. Negative consequences of SMU for adolescent health could include exposures to online forms of aggression. We explored age, gender, and cross-national differences in adolescents engagement in SMU, then relationships between SMU and victimization and the perpetration of cyber-bullying. Methods: We used data on young people aged 11-15 years (weighted n = 180,919 in 42 countries) who participated in the 2017-2018 Health Behaviour in School-aged Children study to describe engagement in the three types of SMU (intense, problematic, and talking with strangers online) by age and gender and then in the perpetration and victimization of cyber-bullying. Relationships between SMU and cyber-bullying outcomes were estimated using Poisson regression (weighted n = 166,647 from 42 countries). Results: Variations in SMU and cyber-bullying follow developmental and gender-based patterns across countries. In pooled analyses, engagement in SMU related to cyber-bullying victimization (adjusted relative risks = 1.14 [95% confidence interval (CI): 1.10-1.19] to 1.48 [95% CI: 1.42-1.55]) and perpetration (adjusted relative risk = 1.31 [95% CI: 1.26-1.36] to 1.84 [95% CI: 1.74-1.95]). These associations were stronger for cyber-perpetration versus cyber-victimization and for girls versus boys. Problematic SMU was most strongly and consistently associated with cyber-bullying, both for victimization and perpetration. Stratified analyses showed that SMU related to cyber-victimization in 19%-45% of countries and to cyber-perpetration in 38%-86% of countries. Conclusions: Accessibility to social media and its pervasive use has led to new opportunities for online aggression. The time adolescents spend on social media, engage in problematic use, and talk to strangers online each relate to cyber-bullying and merit public health intervention. Problematic use of social media poses the strongest and most consistent risk. (C) 2020 Published by Elsevier Inc. on behalf of Society for Adolescent Health and Medicine.
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| 3. |
- Craig, Wendy, et al.
(författare)
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Social Media Use and Cyber-Bullying: A Cross-National Analysis of Young People in 42 Countries
- 2020
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Ingår i: Journal of Adolescent Health. - : Elsevier BV. - 1054-139X .- 1879-1972. ; 66:6
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Social media use (SMU) has become an intrinsic part of adolescent life. Negative consequences of SMU for adolescent health could include exposures to online forms of aggression. We explored age, gender, and cross-national differences in adolescents' engagement in SMU, then relationships between SMU and victimization and the perpetration of cyber-bullying. Methods: We used data on young people aged 11–15 years (weighted n = 180,919 in 42 countries) who participated in the 2017–2018 Health Behaviour in School-aged Children study to describe engagement in the three types of SMU (intense, problematic, and talking with strangers online) by age and gender and then in the perpetration and victimization of cyber-bullying. Relationships between SMU and cyber-bullying outcomes were estimated using Poisson regression (weighted n = 166,647 from 42 countries). Results: Variations in SMU and cyber-bullying follow developmental and gender-based patterns across countries. In pooled analyses, engagement in SMU related to cyber-bullying victimization (adjusted relative risks = 1.14 [95% confidence interval (CI): 1.10–1.19] to 1.48 [95% CI: 1.42–1.55]) and perpetration (adjusted relative risk = 1.31 [95% CI: 1.26–1.36] to 1.84 [95% CI: 1.74–1.95]). These associations were stronger for cyber-perpetration versus cyber-victimization and for girls versus boys. Problematic SMU was most strongly and consistently associated with cyber-bullying, both for victimization and perpetration. Stratified analyses showed that SMU related to cyber-victimization in 19%–45% of countries and to cyber-perpetration in 38%–86% of countries. Conclusions: Accessibility to social media and its pervasive use has led to new opportunities for online aggression. The time adolescents spend on social media, engage in problematic use, and talk to strangers online each relate to cyber-bullying and merit public health intervention. Problematic use of social media poses the strongest and most consistent risk.
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| 5. |
- Den Boer, Wendy, et al.
(författare)
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Climbing adaptations, locomotory disparity and ecological convergence in ancient stem 'kangaroos'
- 2019
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Living kangaroos, wallabies and rat-kangaroos (Macropodoidea) constitute the most ecologically diverse radiation of Australasian marsupials. Indeed, even their hallmark bipedal hopping gait has been variously modified for bounding, walking and climbing. However, the origins of this locomotory adaptability are uncertain because skeletons of the most ancient macropodoids are exceptionally rare. Some of the stratigraphically oldest fossils have been attributed to Balbaridae-a clade of potentially quadrupedal stem macropodoids that became extinct during the late Miocene. Here we undertake the first assessment of balbarid locomotion using two-dimensional geometric morphometrics and a correlative multivariate analysis of linear measurements. We selected the astragalus and pedal digit IV ungual as proxies for primary gait because these elements are preserved in the only articulated balbarid skeleton, as well as some unusual early Miocene balbarid-like remains that resemble the bones of modern tree-kangaroos. Our results show that these fossils manifest character states indicative of contrasting locomotory capabilities. Furthermore, predictive modelling reveals similarities with extant macropodoids that employ either bipedal saltation and/or climbing. We interpret this as evidence for archetypal gait versatility, which probably integrated higher-speed hopping with slower-speed quadrupedal progression and varying degrees of scansoriality as independent specializations for life in forest and woodland settings.
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| 6. |
- den Boer, Wendy, 1987-
(författare)
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Evolutionary Progression of the Iconic Australasian Kangaroos, Rat-Kangaroos, and their Fossil Relatives (Marsupialia: Macropodiformes)
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The exceptionally diverse macropodiform’s (kangaroos, rat-kangaroos and their fossil allies) currently have a fossil record that spans from the late Oligocene to the Holocene with an Australasian widespread fossil occurence. The origins of the macropodiforms are believed to have been during the Eocene possibly having split from the Phalangeridae. This is largely based on molecular data as there is a complete lack of macropodiform fossil material prior to the late Oligocene leaving the origins of the macropodiforms to be largely speculative. Thus, late Oligocene rat-kangaroo dental fossil elements associated with Palaeopotorous priscus (which shares characteristics observed in both phalangerid and macropodiforms) were examined to get a better insight into the potential origins of the macropodiforms. The results obtained suggested that P. priscus is currently the most basal macropodiform known. Furthermore, due to the absence of adequate macropodiform post-cranial material, the functional eco-morphological interpretation of various macropodiform fossil taxa has been based largely on cranial and dental characteristics. Consequently, the examination of Miocene Balbaridae kangaroo’s (Balbaroo nalima and an untaxonomised balbarid) post-cranial elements was undertaken, suggesting an array of locomotion types (similar to living macropodiforms) and a likely persistent arboreal and quadrupedal lifestyle. In addition, the Pleistocene Protemnodon anak’s post-cranial material are examined, proposing a probable combination of quadrupedal bounding and a slow walking gait alternative to the eminent fast bipedal saltation seen in almost all extant macropodiforms.
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