Diversity dynamics in New Caledonia: towards the end of the museum model?

<p>Abstract</p> <p>Background</p> <p>The high diversity of New Caledonia has traditionally been seen as a result of its Gondwanan origin, old age and long isolation under stable climatic conditions (the museum model). Under this scenario, we would expect species diversification to follow a constant rate model. Alternatively, if New Caledonia was completely submerged after its breakup from Gondwana, as geological evidence indicates, we would expect species diversification to show a characteristic slowdown over time according to a diversity-dependent model where species accumulation decreases as space is filled.</p> <p>Results</p> <p>We reanalyze available datasets for New Caledonia and reconstruct the phylogenies using standardized methodologies; we use two ultrametrization alternatives; and we take into account phylogenetic uncertainty as well as incomplete taxon sampling when conducting diversification rate constancy tests. Our results indicate that for 8 of the 9 available phylogenies, there is significant evidence for a diversification slowdown. For the youngest group under investigation, the apparent lack of evidence of a significant slowdown could be because we are still observing the early phase of a logistic growth (i.e. the clade may be too young to exhibit a change in diversification rates).</p> <p>Conclusions</p> <p>Our results are consistent with a diversity-dependent model of diversification in New Caledonia. In opposition to the museum model, our results provide additional evidence that original New Caledonian biodiversity was wiped out during the episode of submersion, providing an open and empty space facilitating evolutionary radiations.</p

Control of style-of-faulting on spatial pattern of earthquake-triggered landslides

Predictive mapping of susceptibility to earthquake-triggered landslides (ETLs) commonly uses distance to fault as spatial predictor, regardless of style-of-faulting. Here, we examined the hypothesis that the spatial pattern of ETLs is influenced by style-of-faulting based on distance distribution analysis and Fry analysis. The Yingxiu–Beichuan fault (YBF) in China and a huge number of landslides that ruptured and occurred, respectively, during the 2008 Wenchuan earthquake permitted this study because the style-of-faulting along the YBF varied from its southern to northern parts (i.e. mainly thrust-slip in the southern part, oblique-slip in the central part and mainly strike-slip in the northern part). On the YBF hanging-wall, ETLs at 4.4–4.7 and 10.3–11.5 km from the YBF are likely associated with strike- and thrust-slips, respectively. On the southern and central parts of the hanging-wall, ETLs at 7.5–8 km from the YBF are likely associated with oblique-slips. These findings indicate that the spatial pattern of ETLs is influenced by style-of-faulting. Based on knowledge about the style-of-faulting and by using evidential belief functions to create a predictor map based on proximity to faults, we obtained higher landslide prediction accuracy than by using unclassified faults. When distance from unclassified parts of the YBF is used as predictor, the prediction accuracy is 80%; when distance from parts of the YBF, classified according to style-of-faulting, is used as predictor, the prediction accuracy is 93%. Therefore, mapping and classification of faults and proper spatial representation of fault control on occurrence of ETLs are important in predictive mapping of susceptibility to ETLs

Morbidity and mortality of patients with endovascularly treated intracerebral aneurysms: does physician specialty matter?

OBJECT Endovascular treatment of cerebrovascular pathology, particularly aneurysms, is becoming more prevalent. There is a wide variety in clinical background and training of physicians who treat cerebrovascular pathology through endovascular means. The impact of clinical training background on patient outcomes is not well documented. METHODS The authors conducted a retrospective analysis of a large national database, the University HealthSystem Consortium, that was queried in the years 2009-2013. Cases of both unruptured cerebral aneurysms and subarachnoid hemorrhage treated by endovascular obliteration were studied. Outcome measures of morbidity and mortality were evaluated according to the specialty of the treating physician. RESULTS Elective embolization of an unruptured aneurysm was the procedure code and primary diagnosis, respectively, for 12,400 cases. Patients with at least 1 complication were reported in 799 cases (6.4%). Deaths were reported in 193 cases (1.6%). Complications and deaths were varied by specialty; the highest incidence of complications (11.1%) and deaths (3.0%) were reported by neurologists. The fewest complications were reported by neurosurgeons (5.4%; 1.4% deaths), with a higher incidence of complications reported in cases performed by neurologists (p \u3c 0.0001 for both complications and deaths) and to a lesser degree interventional radiologists (p = 0.0093 for complications). Subarachnoid hemorrhage was the primary diagnosis and procedure for 8197 cases. At least 1 complication was reported in 2385 cases (29%) and deaths in 983 cases (12%). The number of complications and deaths varied among specialties. The highest incidence of complications (34%) and deaths (13.5%) in subarachnoid hemorrhage was in cases performed by neurologists. The fewest complications were in cases by neurosurgeons (27%), with a higher incidence of complications in cases performed by neurologists (34%, p \u3c 0.0001), and a trend of increased complications with interventional radiologists (30%, p \u3c 0.0676). The lowest incidence of mortality was in cases performed by neurosurgeons (11.5%), with a significantly higher incidence of mortality in cases performed by neurologists (13.5%, p = 0.0372). Mortality rates did not reach statistical significance with respect to interventional radiologists (12.1%, p = 0.4884). CONCLUSIONS Physicians of varied training types and backgrounds use endovascular treatment of ruptured and unruptured intracerebral aneurysms. In this study there was a statistically significant finding that neurosurgically trained physicians may demonstrate improved outcomes with respect to endovascular treatment of unruptured aneurysms in this cohort. This finding warrants further investigation

Endarterectomia de carótida sob anestesia local: evolução de 104 pacientes Carotid endarterectomy under regional anesthesia: follow-up of 104 patients

A estenose carotídea cervical é uma das causas mais freqüentes de acidente vascular cerebral isquêmico. A endarterectomia de carótida é um tratamento eficaz para lesões estenóticas moderadas e graves, tanto sintomáticas quanto assintom��ticas. A endarterectomia realizada sob anestesia local permite a monitorização neurológica do paciente durante o ato cirúrgico. O objetivo deste trabalho foi avaliar as complicações cirúrgicas e acompanhar a evolução dos pacientes submetidos a endarterectomia sob anestesia local em nossa instituição, comparando os resultados com outras publicações. 104 pacientes foram submetidos a 110 procedimentos no período de abril de 1996 a maio de 2002. 64 pacientes eram sintomáticos (61,54%) e 40 assintomáticos (38,46%). Todos possuíam grau de estenose carotídea igual ou superior a 70%. Os pacientes foram avaliados retrospectivamente. O tempo de evolução variou de um a 72 meses (média: 29,5). Três pacientes apresentaram hematoma cervical necessitando drenagem cirúrgica. Dois pacientes (1,92%) tiveram acidente vascular cerebral do mesmo lado da endarterectomia no pós-operatório e outros dois durante o seguimento. Dois pacientes faleceram em decorrência da cirurgia (1,92%). Os resultados desta série, comparados com a literatura, permitem concluir que a endarterectomia é uma forma segura de tratamento para as estenoses carotídeas moderadas e graves.<br>Cervical carotid stenosis is one of the main causes of ischemic stroke. Carotid endarterectomy is a safe procedure for treatment of moderate and severe symptomatic and asymptomatic carotid stenosis. Regional anesthesia allows neurological evaluation of the patient during the surgery. We reviewed the results of 104 patients operated on at our institution under regional anesthesia during the period of April 1996 and May 2002. 64 patients were symptomatic (61.54%) and 40 asymptomatic (38.46%). All patients had carotid stenosis over 70%. The patients were followed from one to 72 months (Mean: 29.5). Three patients had cervical hematoma, that required surgical drainage. Two patients had minor stroke at the same side of the endarterectomy at the post-operative period and another two during the follow-up (1.92%). Two patients died due to complications related to the surgery (1.92%). Our results, compared with the literature, show that endarterectomy is a safe procedure to treat moderate or severe carotid artery stenosis

Neurosurgical education in Europe and the United States of America

Training in neurological surgery is one of the most competitive and demanding specializations in medicine. It therefore demands careful planning in both the scientific and clinical neurosurgery arena to finally turn out physicians that can be clinically sound and scientifically competitive. National and international training and career options are pointed out, based on the available relevant literature, with the objective of comparing the neurosurgical training in Europe and the USA. Despite clear European Association of Neurosurgical Societies guidelines, every country in Europe maintains its own board requirements, which is reflected in an institutional curriculum that is specific to the professional society of that particular country. In contrast, the residency program in the USA is required to comply with the Accreditation Council for Graduate Medical Education guidelines. Rather similar guidelines exist for the education of neurosurgical residents in the USA and Europe; their translation into the practical hospital setting and the resulting clinical lifestyle of a resident diverges enormously. Since neurosurgical education remains heterogeneous worldwide, we argue that a more standardized curriculum across different nations would greatly facilitate the interaction of different centers, allow a direct comparison of available services, and support the exchange of vital information for quality control and future improvements. Furthermore, the exchange of residents between different training centers may improve education by increasing their knowledge base, both technically as well as intellectually