18 research outputs found

    Comprehensive inventory of true flies (Diptera) at a tropical site

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    Estimations of tropical insect diversity generally suffer from lack of known groups or faunas against which extrapolations can be made, and have seriously underestimated the diversity of some taxa. Here we report the intensive inventory of a four-hectare tropical cloud forest in Costa Rica for one year, which yielded 4332 species of Diptera, providing the first verifiable basis for diversity of a major group of insects at a single site in the tropics. In total 73 families were present, all of which were studied to the species level, providing potentially complete coverage of all families of the order likely to be present at the site. Even so, extrapolations based on our data indicate that with further sampling, the actual total for the site could be closer to 8000 species. Efforts to completely sample a site, although resource-intensive and time-consuming, are needed to better ground estimations of world biodiversity based on limited sampling

    New insights into the genetic etiology of Alzheimer's disease and related dementias

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    Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

    Genome-wide association meta-analysis identifies five novel loci for age-related hearing impairment

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    Previous research has shown that genes play a substantial role in determining a person's susceptibility to age-related hearing impairment. The existing studies on this subject have different results, which may be caused by difficulties in determining the phenotype or the limited number of participants involved. Here, we have gathered the largest sample to date (discovery n = 9,675; replication n = 10,963; validation n = 356,141), and examined phenotypes that represented low/mid and high frequency hearing loss on the pure tone audiogram. We identified 7 loci that were either replicated and/or validated, of which 5 loci are novel in hearing. Especially the ILDR1 gene is a high profile candidate, as it contains our top SNP, is a known hearing loss gene, has been linked to age-related hearing impairment before, and in addition is preferentially expressed within hair cells of the inner ear. By verifying all previously published SNPs, we can present a paper that combines all new and existing findings to date, giving a complete overview of the genetic architecture of age-related hearing impairment. This is of importance as age-related hearing impairment is highly prevalent in our ageing society and represents a large socio-economic burden

    A review of Scatellini (Diptera: Ephydridae) from Brazil

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    Scatellini was proposed by Wirth & Stone, 1956 and currently includes 242 described species in nine genera­. The tribe has representatives in all biogeographic regions and about 70 species occur in the Neotropical Region. Prior to this study, only two species were recorded from Brazil: Scatella obscura and Limnellia itatiaia. In this paper, species of Scatellini from Brazil are reviewed with an emphasis on the fauna from southern Brazil, where six new species have been discovered and are described herein: Scatella praia, S. plaumanni, S. rara, Scatophila darrowae, S. dianneae, and S. prainha. To facilitate identification of the tribe and included genera and species, we have included diagnoses of these taxa and have also provided an annotated key to the Neotropical genera in Scatellini. We have also provided illustrations of structures of the male terminalia of all included species of the genus Scatophila

    A review of the Neotropical species of the shore-fly genera Orasiopa and Pectinifer (Diptera: Ephydridae)

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    ABSTRACT Species of two genera of the tribe Discocerinini from the Neotropics are reviewed with an emphasis on the fauna from Brazil. The two species, Orasiopa (Reymontopa ) mera (Cresson, 1939) and Pectinifer aeneus (Cresson, 1918), are described, illustrated and new occurrence data are provided. Phylogenetic relationships of these two genera into the tribe are discussed. To facilitate identification of these species, we have included diagnoses of the Discocerinini and both genera and have also provided an annotated key to the New World genera in this tribe. We have also provided illustrations, photographs, and scanning electron micrographs of external structures and of structures of the male terminalia for included species
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