Developmental constraints do not influence long-term phenotypic evolution of marsupial forelimbs as revealed by interspecific disparity and integration patterns.

Política de acceso abierto tomada de: https://www.journals.uchicago.edu/openMarsupials show a smaller range of forelimb ecomorphologies than placental mammals, and it is hypothesized that this results from macroevolutionary constraints imposed by the specialized reproductive biology of marsupials. Specifically, the accelerated development of the marsupial forelimb allows neonates to crawl to the mother’s pouch but may constrain adult morphology. This hypothesis makes three main predictions: (i) that marsupial forelimbs should show less interspecific disparity than their hindlimbs, (ii) that morphological integration within the marsupial forelimb is stronger than integration between limbs, and (iii) that these patterns should be strongest in diprotodontians, which undergo the most rigorous crawls as neonates. We use a three-dimensional geometric morphometric data set of limb bones for 51 marsupial species to test these predictions. We find that (i) marsupial forelimbs and hindlimbs show similar disparities, (ii) no clear differences in integration exist either within or between limbs, and (iii) the same patterns occur in diprotodontians as in other marsupials, even correcting for lineage age. Therefore, there is currently little evidence that the developmental biology of marsupials has constrained their macroevolutionary patterns. It is possible that functional selection can overcome the effects of developmental constraint on macroevolutionary timescales. Our findings suggest that the role of developmental constraints in explaining the limited phenotypic variability of marsupials (compared with that of placentals) should be reconsidere

The latitudinal biodiversity gradient through deep time

Today, biodiversity decreases from equatorial to polar regions. This is a fundamental pattern governing the distribution of extant organisms, the understanding of which is critical to predicting climatically driven biodiversity loss. However, its causes remain unresolved. The fossil record offers a unique perspective on the evolution of this latitudinal biodiversity gradient (LBG), providing a dynamic system in which to explore spatiotemporal diversity fluctuations. Deep-time studies indicate that a tropical peak and poleward decline in species diversity has not been a persistent pattern throughout the Phanerozoic, but is restricted to intervals of the Palaeozoic and the past 30 million years. A tropical peak might characterise cold icehouse climatic regimes, whereas warmer greenhouse regimes display temperate diversity peaks or flattened gradients

Virtual reconstruction of the endocranial anatomy of the early Jurassic marine crocodylomorph Pelagosaurus typus (Thalattosuchia)

Thalattosuchia is a radiation of aquatic crocodylomorphs that attained a worldwide distribution at low latitudes during the Early Jurassic—Early Cretaceous (Mannion et al., 2015). They are characterized by having a longirostrine skull morphology (long, narrow snout), although some taxa possessed relatively shorter and more robust snouts (e.g., Dakosaurus; Gasparini, Pol & Spalletti, 2006). The group is divided into two major clades, the teleosauroids, which were ‘gavial-like’ near shore predators, and the highly-derived pelagic metriorhynchoids (i.e., metriorhynchids), which exhibited modified flipper-like forelimbs, a crescentic fish-like tail, and loss of dermal armour. The morphology, phylogeny, and evolutionary dynamics of the Thalattosuchia has been under intense investigation over the past decade (e.g., Mueller-Töwe, 2005; Mueller-Töwe, 2006; Jouve, 2009; Pierce, Angielczyk & Rayfield, 2009a; Pol & Gasparini, 2009; Young & De Andrade, 2009; Young et al., 2010; Young, Bell & Brusatte, 2011; Martin & Vincent, 2013; Stubbs et al., 2013; Cau, 2014; Martin et al., 2014; Jouve et al., 2016; Young et al., 2016) with some recent studies suggesting that thalattosuchians may be relatively early diverging members of the Crocodyliformes (e.g., Wilberg, 2015a). Moreover, there has been increasing interest in reconstructing their functional paleoecology, with studies focusing on feeding mechanics and niche partitioning (e.g., Pierce, Angielczyk & Rayfield, 2009b; De Andrade et al., 2010; Young et al., 2010; Stubbs et al., 2013; Young et al., 2013), as well as adaptations for aquatic locomotion (e.g., Hua, 1994; Hua & De Buffrenil, 1996; Hua, 2003; Molnar et al., 2015)

Course and predictors of posttraumatic stress and depression longitudinal symptom profiles in refugees:A latent transition model

Exposure to potentially traumatic events and post-migration living difficulties (PMLDs) may explain the high rates of posttraumatic stress disorder (PTSD) and depression in resettled refugees. Latent class analyses (LCAs) in refugees have identified subgroups that differ in symptom profiles of PTSD and comorbid symptoms. However, knowledge on longitudinal symptom profiles in refugees is sparse. Examining longitudinal PTSD and depression symptom profiles could provide information on risk factors underlying worsening of symptoms post-resettlement. Self-rated PTSD (Posttraumatic Diagnostic Scale) and depression (Patient Health Questionnaire-9) symptoms were assessed among 613 refugees who had resettled in Australia up to two years previously (W1) and at 6 months follow-up (W2). PTSD and depression symptom profiles were identified using LCAs for W1 and W2 separately. Latent transition analysis was used to examine (predictors of) changes in symptom profiles, including gender, age, trauma exposure, and PMLDs. Four classes were identified that were consistent across timepoints: a No symptoms (W1 61%; W2 68%), Low PTSD/Moderate depression (W1 16%; W2 10%), Moderate PTSD/depression (W1 16%; W2 14%), and High symptoms class (W1 7%; W2 7%). Higher levels of problems with PMLDs, including being discrimination and family separation, predicted movements out of the No symptom class at W1 to classes with psychopathology at W2. To conclude, most participants did not develop PTSD or depression symptoms. The risk of developing these symptoms seems higher when problems with interpersonal PMLDs increased, pointing to the need for considering these stressors when addressing the mental health needs in this population

Psychometric assessment of the short-form Child Perceptions Questionnaire: an international collaborative study.

OBJECTIVE: To examine the factor structure and other psychometric characteristics of the most commonly used child oral-health-related quality-of-life (OHRQoL) measure (the 16-item short-form CPQ11-14 ) in a large number of children (N = 5804) from different settings and who had a range of caries experience and associated impacts. METHODS: Secondary data analyses used subnational epidemiological samples of 11- to 14-year-olds in Australia (N = 372), New Zealand (three samples: 352, 202, 429), Brunei (423), Cambodia (244), Hong Kong (542), Malaysia (439), Thailand (220, 325), England (88, 374), Germany (1055), Mexico (335) and Brazil (404). Confirmatory factor analysis (CFA) was used to examine the factor structure of the CPQ11-14 across the combined sample and within four regions (Australia/NZ, Asia, UK/Europe and Latin America). Item impact and internal reliability analysis were also conducted. RESULTS: Caries experience varied, with mean DMFT scores ranging from 0.5 in the Malaysian sample to 3.4 in one New Zealand sample. Even more variation was noted in the proportion reporting only fair or poor oral health; this was highest in the Cambodian and Mexican samples and lowest in the German sample and one New Zealand sample. One in 10 reported that their oral health had a marked impact on their life overall. The CFA across all samples revealed two factors with eigenvalues greater than 1. The first involved all items in the oral symptoms and functional limitations subscales; the second involved all emotional well-being and social well-being items. The first was designated the 'symptoms/function' subscale, and the second was designated the 'well-being' subscale. Cronbach's alpha scores were 0.72 and 0.84, respectively. The symptoms/function subscale contained more of the items with greater impact, with the item 'Food stuck in between your teeth' having greatest impact; in the well-being subscale, the 'Felt shy or embarrassed' item had the greatest impact. Repeating the analyses by world region gave similar findings. CONCLUSION: The CPQ11-14 performed well cross-sectionally in the largest analysis of the scale in the literature to date, with robust and mostly consistent psychometric characteristics, albeit with two underlying factors (rather than the originally hypothesized four-factor structure). It appears to be a sound, robust measure which should be useful for research, practice and policy

Structural Determinants and Children's Oral Health: A Cross-National Study

Much research on children's oral health has focused on proximal determinants at the expense of distal (upstream) factors. Yet, such upstream factors-the so-called structural determinants of health-play a crucial role. Children's lives, and in turn their health, are shaped by politics, economic forces, and social and public policies. The aim of this study was to examine the relationship between children's clinical (number of decayed, missing, and filled teeth) and self-reported oral health (oral health-related quality of life) and 4 key structural determinants (governance, macroeconomic policy, public policy, and social policy) as outlined in the World Health Organization's Commission for Social Determinants of Health framework. Secondary data analyses were carried out using subnational epidemiological samples of 8- to 15-y-olds in 11 countries ( N = 6,648): Australia (372), New Zealand (three samples; 352, 202, 429), Brunei (423), Cambodia (423), Hong Kong (542), Malaysia (439), Thailand (261, 506), United Kingdom (88, 374), Germany (1498), Mexico (335), and Brazil (404). The results indicated that the type of political regime, amount of governance (e.g., rule of law, accountability), gross domestic product per capita, employment ratio, income inequality, type of welfare regime, human development index, government expenditure on health, and out-of-pocket (private) health expenditure by citizens were all associated with children's oral health. The structural determinants accounted for between 5% and 21% of the variance in children's oral health quality-of-life scores. These findings bring attention to the upstream or structural determinants as an understudied area but one that could reap huge rewards for public health dentistry research and the oral health inequalities policy agenda

A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China

The Early Cretaceous fossil record of large−bodied theropods from Asia is poor, hindering comparison of Asian predatory dinosaur faunas with those from other continents. One of the few large Asian theropod specimens from this interval is a partial skull (maxilla and dentary) from the Lianmugin Formation (?Valanginian–Albian), the holotype of Kelmayisaurus petrolicus. Most authors have either considered this specimen as an indeterminate basal tetanuran or a nomen dubium. Weredescribe K. petrolicus and note that it possesses a single autapomorphy (a deep accessory groove on the lateral surface of the anterior dentary), as well as a unique combination of characters that differentiates it from other theropods, affirming its validity. A phylogenetic analysis recovers K. petrolicus as a basal carcharodontosaurid, which is supported by various features: very deep interdental plates (a carcharodontosaurid synapomorphy), fused interdental plates (present in carchardontosaurids and a limited number of other theropods), and the absence of diagnostic features of other clades of large−bodied theropods such as abelisaurids, megalosauroids, and coelurosaurs. As such, Kelmayisaurus is the second known carcharodontosaurid from Asia, and further evidence that this clade represented a global radiation of large−bodied predators during the Early–mid Cretaceous