302 research outputs found

    Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance

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    Medullary bone is a special bone tissue forming on the endosteal surface of the medullary cavity in the bones of female birds prior to and during egg-laying to serve as a calcium reservoir for building the hard eggshell. It has also been identified in non-avian dinosaurs, where its presence is considered as a reliable indicator of a sexually mature female. Here, we reveal that multiple mandibular symphyses of the azhdarchid pterosaur Bakonydraco galaczi possess a special bone tissue that shows all microanatomical, histological, and developmental characteristics of medullary bone, despite its unusual location. Its frequent occurrence in the sample renders a pathologic origin unlikely. Our findings as well as the extremely thin-shelled eggs of pterosaurs suggest that this medullary bone-like tissue probably had a non-reproductive role in these animals. Although the non-reproductive significance and the anatomical location of this medullary bone-like tissue in Bakonydraco suggest independent evolutionary appearance from dinosaurian medullary bone, a common origin and later diverging function and physiological regulation is an equally viable phylogenetic hypothesis

    The assessment and treatment of panic disorder in general practice

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    Panic disorder (PD) is an anxiety disorder that affects many South Africans. If undiagnosed or mismanaged, this condition may impact profoundly on an individual's functioning and quality of life. At the primary level, the assessment of panic attacks requires consideration of a number of differential diagnoses. General practitioners also play an invaluable role in the acute and long-term care and appropriate referral of individuals with PD. This article provides an overview of PD in general practice and includes a guideline for case identification and therapeutic options

    Long bone histology of basalmost and derived Sauropodomorpha : the convergence of fibrolamellar bone and the evolution of giantism and nanism

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    This study reports on long bone histology and growth in sauropodomorph dinosaurs. Derived members of Sauropodomorpha, the sauropods, were the largest terrestrial animals our planet has ever seen. New methods have recently allowed a much better sampling coverage, and provided a uniform view of uninterrupted laminar fibrolamellar bone (FLB) in neosauropods, but more basal sauropodomorphs remained unclear. Results in the current work indicate that FLB was already present in the earliest sauropodomorphs. Saturnalia, one of the most basal sauropodomorphs, clearly shows FLB in its long bones, albeit with growth marks. These marks represent interruptions of the animal’s growth, and are also present in other basal sauropodomorphs like Thecodontosaurus and Plateosaurus. This confirms earlier studies that sauropods accelerated their growth rates, most likely made possible by the preadaptive presence of high basal metabolic rates. FLB in mammals probably evolved as a convergent feature. Osteocyte lacuna densities and sizes suggest that sauropodomorphs and mammals employed different cell strategies to build bone tissue. However, a conclusion that FLB originated in a single archosaur or archosauromorph ancestor of sauropodomorphs and saurischians in general needs further testing. Long bone microstructure thus partially accounts for how these animals grew to giants, or became dwarfs in some cases. Sauropods namely secundarily evolved small sizes on islands. Here we provide strong evidence that the titanosaur Magyarosaurus dacus from the Cretaceous of Romania is not a juvenile of the larger ‘M.’ hungaricus . M. dacus individuals are histologically mature and have a different ontogenetic trajectory than ‘M.’ hungaricus. The histology of M. dacus is different from Europasaurus, a basal titanosauriform island dwarf from the Late Jurassic of Germany. The more intense secondary remodelling of M. dacus may be explaned by peramorphic heterochrony, possibly coupled with increased pneumatization in Titanosauria. The selective forces behind the progenetic dwarfing (a form of paedomorphosis) probably include the absence of large predators, and insufficient resources to provide for a healthy population of very large sauropods, and dinosaurs in general. Other dwarfed dinosaur species from the Hatzeg Basin like the ornithopods Zalmoxes and Telmatosaurus confirm this hypothesis

    Quality of life and symptom intensity over time in people with cancer receiving palliative care : results from the international European Palliative Care Cancer Symptom study

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    Background People with advanced cancer experience multiple symptoms during their illness trajectory, which can fluctuate in intensity. Aim To describe the course of self-reported quality of life, emotional functioning, physical functioning and symptom intensity over time in cancer patients receiving palliative care. Design Longitudinal study with monthly assessments, using the EORTC QLQ-C15-PAL. Data were analysed (1) prospectively, from baseline to >= 8-month follow-up; and (2) retrospectively, by taking death as index date and comparing results from three cross-sectional subsamples at different stages of illness (time to death >= 6, 5-3 and 2-0 months). Linear mixed models were calculated. Setting/participants A total of 1739 patients (mean age 66, 50% male) from 30 palliative care centers in 12 countries were included. Results In prospective analyses, quality of life, functioning and symptoms-except nausea/vomiting-remained generally stable over time. In retrospective analyses, patients 2-0 months before death reported significantly lower quality of life and physical functioning scores than those 5-3 months before death, who in turn scored lower than those >= 6 months before death, suggesting progressive decline. Emotional functioning remained initially unchanged, but decreased in the last months. Pain, fatigue and appetite loss showed a stable increase in intensity towards death. Dyspnea, insomnia and constipation increased from 5-3 to 2-0 months before death. Nausea/vomiting only increased when comparing those >= 6 months before death with those 2-0 months before death. Conclusion While the prospective approach showed predominantly stable patterns for quality of life, functioning and symptom severity throughout study duration, retrospective analyses indicated that deterioration was already apparent before the terminal phase and accelerated close to death. Our findings support the importance of early symptom identification and treatment in this population, and highlight the need for further studies to explore what characterizes those with either lower or higher symptom burden at different time points towards death

    Life History of Rhamphorhynchus Inferred from Bone Histology and the Diversity of Pterosaurian Growth Strategies

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    Rhamphorhynchus from the Solnhofen Limestones is the most prevalent long tailed pterosaur with a debated life history. Whereas morphological studies suggested a slow crocodile-like growth strategy and superprecocial volant hatchlings, the only histological study hitherto conducted on Rhamphorhynchus concluded a relatively high growth rate for the genus. These controversial conclusions can be tested by a bone histological survey of an ontogenetic series of Rhamphorhynchus.Our results suggest that Bennett's second size category does not reflect real ontogenetic stage. Significant body size differences of histologically as well as morphologically adult specimens suggest developmental plasticity. Contrasting the 'superprecocial hatchling' hypothesis, the dominance of fibrolamellar bone in early juveniles implies that hatchlings sustained high growth rate, however only up to the attainment of 30-50% and 7-20% of adult wingspan and body mass, respectively. The early fast growth phase was followed by a prolonged, slow-growth phase indicated by parallel-fibred bone deposition and lines of arrested growth in the cortex, a transition which has also been observed in Pterodaustro. An external fundamental system is absent in all investigated specimens, but due to the restricted sample size, neither determinate nor indeterminate growth could be confirmed in Rhamphorhynchus.The initial rapid growth phase early in Rhamphorhynchus ontogeny supports the non-volant nature of its hatchlings, and refutes the widely accepted 'superprecocial hatchling' hypothesis. We suggest the onset of powered flight, and not of reproduction as the cause of the transition from the fast growth phase to a prolonged slower growth phase. Rapidly growing early juveniles may have been attended by their parents, or could have been independent precocial, but non-volant arboreal creatures until attaining a certain somatic maturity to get airborne. This study adds to the understanding on the diversity of pterosaurian growth strategies

    Prevalence of lifestyle cardiovascular risk factors and estimated framingham 10-year risk scores of adults with psychotic disorders compared to controls at a referral hospital in Eldoret, Kenya

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    Introduction: Lifestyle factors such as smoking, alcohol use, suboptimal diet, and inadequate physical activity have been associated with increased risk of cardiovascular diseases. There are limited data on these risk factors among patients with psychosis in low- and middle-income countries. Objectives: This study aimed to establish the prevalence of lifestyle cardiovascular risk factors, and the 10-year cardiovascular risk scores and associated factors in patients with psychosis compared to controls at Moi Teaching and Referral Hospital in Eldoret, Kenya. Methods: A sample of 297 patients with schizophrenia, schizoaffective disorder, or bipolar mood disorder; and 300 controls matched for age and sex were included in this analysis. A study specific researcher-administered questionnaire was used to collect data on demographics, antipsychotic medication use, smoking, alcohol intake, diet, and physical activity. Weight, height, abdominal circumference, and blood pressure were also collected to calculate the Framingham 10-year Cardiovascular Risk Score (FRS), while blood was drawn for measurement of glucose level and lipid profile. Pearson’s chi-squared tests and t-tests were employed to assess differences in cardiovascular risk profiles between patients and controls, and a linear regression model was used to determine predictors of 10-year cardiovascular risk in patients. Results: Compared to controls, patients with psychosis were more likely to have smoked in their lifetimes (9.9% vs. 3.3%, p = 0.006) or to be current smokers (13.8% vs. 7%, p = 0.001). Over 97% of patients with psychosis consumed fewer than five servings of fruits and vegetables per week; 78% engaged in fewer than three days of vigorous exercise per week; and 48% sat for more than three hours daily. The estimated 10-year risk of CVD was relatively low in this study: the FRS in patients was 3.16, compared to 2.93 in controls. The estimated 10-year cardiovascular risk in patients was significantly associated with female sex (p = 0.007), older patients (p \u3c 0.001), current tobacco smoking (p \u3c 0.001), and metabolic syndrome (p \u3c 0.001). Conclusion: In the setting of Eldoret, there is suboptimal physical exercise and intake of healthy diet among patients with psychosis and controls. While the estimated risk score among patients is relatively low in our study, these data may be useful for informing future studies geared towards informing interventions to promote healthy lifestyles in this population

    Ontogeny of Hemidactylus (Gekkota, Squamata) with emphasis on the limbs

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    Squamate reptiles constitute a major component of the world's terrestrial vertebrate diversity, encompassing many morphotypes related to ecological specialization. Specifically, Gekkota, the sister clade to most other squamates, have highly specialized autopodia, which have been linked to their ecological plasticity. In this study, a developmental staging table of the gecko Hemidactylus, housed at the Museum fur Naturkunde, is established. Twelve post-ovipositional stages are erected, monitoring morphological embryological transitions in eye, ear, nose, heart, limbs, pharyngeal arches, and skin structures. Ecomorphological specializations in the limbs include multiple paraphalanges, hypothesized to aid in supporting the strong muscles, that are situated adjacent to metacarpal and phalangeal heads. Furthermore, some phalanges are highly reduced in manual digits III and IV and pedal digits III, IV, and V. Development, composition, and growth of limb elements is characterized in detail via mu CT, histochemistry, and bone histological analysis. Using known life history data from two individuals, we found an average lamellar bone accretion rate in the humeral diaphysis comparable to that of varanids. Various adult individuals also showed moderate to extensive remodeling features in their long bone cortices, indicating that these animals experience a highly dynamic bone homeostasis during their growth, similar to some other medium-sized to large squamates. This study of in-ovo development of the gecko Hemidactylus and its ecomorphological specializations in the adult autopodia, enlarges our knowledge of morphological trait evolution and of limb diversity within the vertebrate phylum.Peer reviewe

    Extreme tooth enlargement in a new Late Cretaceous rhabdodontid dinosaur from Southern France

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    International audienceRhabdodontidae is a successful clade of ornithopod dinosaurs, characteristic of Late Cretaceous continental faunas in Europe. A new rhabdodontid from the late Campanian, of southern France, Matheronodon provincialis gen. et sp. nov., is characterized by the extreme enlargement of both its maxillary and dentary teeth, correlated to a drastic reduction in the number of maxillary teeth (4 per generation in MMS/VBN-02-102). The interalveolar septa on the maxilla are alternately present or resorbed ventrally so as to be able to lodge such enlarged teeth. The rhabdodontid dentition and masticatory apparatus were adapted for producing a strict and powerful shearing action, resembling a pair of scissors. With their relatively simple dentition, contrasting with the sophisticated dental batteries in contemporary hadrosaurids, Matheronodon and other rhabdodontids are tentatively interpreted as specialized consumers of tough plant parts rich in sclerenchyma fibers, such as Sabalites and Pandanites
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