Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Jejunal perforation caused by abdominal angiostrongyliasis Perfuração jejunal causada por angiostrongilíase abdominal

The authors describe a case of abdominal angiostrongyliasis in an adult patient presenting acute abdominal pain caused by jejunal perforation. The case was unusual, as this affliction habitually involves the terminal ileum, appendix, cecum or ascending colon. The disease is caused by the nematode Angiostrongylus costaricensis, whose definitive hosts are forest rodents while snails and slugs are its intermediate hosts. Infection in humans is accidental and occurs via the ingestion of snail or slug mucoid secretions found on vegetables, or by direct contact with the mucus. Abdominal angiostrongyliasis is clinically characterized by prolonged fever, anorexia, abdominal pain in the right-lower quadrant, and peripheral blood eosinophilia. Although usually of a benign nature, its course may evolve to more complicated forms such as intestinal obstruction or perforation likely to require a surgical approach. Currently, no efficient medication for the treatment of abdominal angiostrongyliasis is known to be available. In this study, the authors provide a review on the subject, considering its etiopathogeny, clinical picture, diagnosis and treatment.<br>Os autores descrevem caso de angiostrongilíase abdominal em doente adulto que se manifestou como abdômen agudo devido à perfuração de alça jejunal, evento raro, uma vez que esta afecção geralmente envolve o íleo terminal, apêndice, ceco ou cólon ascendente. A doença é causada pelo nematódeo Angiostrongylus costaricensis cujos hospedeiros definitivos são roedores silvestres e os hospedeiros intermediários são caracóis e caramujos. A infecção em humanos é acidental e ocorre pela ingestão de secreção mucóide destes invertebrados presentes em vegetais ou por contato direto com o muco. A angiostrongilíase abdominal é clinicamente caracterizada pela presença de febre prolongada, anorexia, dor no quadrante inferior direito do abdômen e eosinofilia periférica. Embora a doença seja de natureza benigna, seu curso pode evoluir para formas complicadas como a obstrução ou perfuração intestinais que necessitam de tratamento cirúrgico. Atualmente, não há tratamento medicamentoso eficaz para a angiostrongilíase abdominal. Neste estudo, os autores realizam uma revisão desta afecção em relação à sua etiopatogenia, quadro clínico diagnóstico e tratamento

Recent advances in psychoneuroimmunology: inflammation in psychiatric disorders

Psychiatric disorders are common and complex and their precise biological underpinnings remain elusive. Multiple epidemiological, molecular, genetic and gene expression studies suggest that immune system dysfunction may contribute to the risk for developing psychiatric disorders including schizophrenia, bipolar disorder, and major depressive disorder. However, the precise mechanisms by which inflammation-related events confer such risk are unclear. In this review, we examine the peripheral and central evidence for inflammation in psychiatric disorders and the potential molecular mechanisms implicated including inhibition of neurogenesis, apoptosis, the HPA-axis, the role of brain-derived neurotrophic factor and the interplay between the glutamatergic, dopaminergic and serotonergic neurotransmitter systems