14 research outputs found
MicroRNA: A signature for cancer progression
Get PDFMicroRNAs (miRNAs) are a group of small non-coding RNAs that post-transcriptionally control expression of genes by targeting mRNAs. miRNA alterations partake in the establishment and progression of different types of human cancer. Consequently, expression profiling of miRNA in human cancers has correlations with cancer detection, staging, progression, and response to therapies. Particularly, amplification, deletion, abnormal pattern of epigenetic factors and the transcriptional factors that mediate regulation of primary miRNA frequently change the landscape of miRNA expression in cancer. Indeed, changes in the quantity and quality of miRNAs are associated with the initiation of cancer, its progression and metastasis. Additionally, miRNA profiling has been used to categorize genes that can affect oncogenic pathways in cancer. Here, we discuss several circulating miRNA signatures, their expression profiles in different types of cancer and their impacts on cellular processes
Bats of Antigua, Northern Lesser Antilles
Get PDFNo comprehensive survey of the chiropteran fauna of the Antillean island of Antigua has been undertaken in the past. Seven species of bats have been reported in the literature from the island previously, but these have appeared in scattered reports. The first report of bats from Antigua was by Allen (1 890) when he reported a single specimen of Noctilio leporinus and two of Artibeus jamaicensis obtained during an ornithological survey of Antillean islands. Subsequent collections of bats on Antigua were incidental to herpetological work or paleontological surveys of Antiguals limestone cave systems. We found 138 voucher specimens from Antigua scattered in eight museums from previous collecting efforts. Before 2000, almost all extant vouchers with locality data were collected from the vicinity of Bats Cave, situated on the southeast corner of the island near the town of English Harbour in the Parish of St. Paul. The first formal survey of Antiguan bats was performed by Matthew Morton and Kevel Lindsay in 1994. Although some mist-netting was conducted, their work focused on roost surveys. aiming to provide a resource for future work concerning sites that would benefit from local conservation efforts and further study. The surveys conducted by parties led by Scott Pedersen in June 1998, July-August 2000, and June 2003 provide the first significant results from mist-netting bats in a variety of foraging habitats on Antigua. Because the southwestern quadrant of the island was under-represented in previous survey efforts, the primary goal of the 2000 and 2003 surveys was to focus upon this forested region and possibly provide new species records for Antigua. The secondary goal of the survey was to provide comparative data for ongoing research into the impact of natural disasters on the bat population on the adjacent island of Montserrat (Adams and Pedersen 1999; Pedersen 2001 ; Pedersen et al., in prep.)
Bats of Montserrat: Population Fluctuation and Response to Hurricanes and Volcanoes, 1978-2005
Get PDFNone of the species of bats occurring in the northern Lesser Antilles is endemic to that region, suggesting considerable dispersal among islands. However, movement patterns of bats in the Lesser Antilles are poorly known and thought to be limited because interisland distances present barriers to dispersal for most species. Genetic data imply restricted dispersal among the islands for the cave-roosting Brachyphylla caoernarum, whereas Artibeus jamaicensis apparently moves among the islands more freely (Carstens et al. 2004). Nevertheless, we do not believe that Antillean bats strike out on their own on a regular basis to move over water from one island to another. It is our conclusion, based on the available data, that stochastic tropical storms and hurricanes moving primarily from southeast to northwest effect dispersal and gene flow for bat populations living in the Lesser Antilles.
Strong hurricanes and volcanic activity are powerful agents of ecological and evolutionary change throughout this archipelago. However, despite the great fluctuations in bat abundance on Montserrat over the last 30 years, none of the species of bats has been extirpated as a result of the dramatic impact of volcanic devastation and a category 5 hurricane. Were these disasters simply insufficient to impact bat biodiversity on Montserrat? Is there a disturbance frequency and severity threshold for bat extirpation, or could it be that we are observing the resilience of a metapopulation in the northern Lesser Antilles
SPEEK/Polyimide Blends for Proton Conductive MembranesPresented at the 1st CARISMA Conference, Progress MEA 2008, La Grande Motte, 21st-24th September 2008.
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