30 research outputs found
Unified Methods in Collecting, Preserving, and Archiving Coral Bleaching and Restoration Specimens to Increase Sample Utility and Interdisciplinary Collaboration
Coral reefs are declining worldwide primarily because of bleaching and subsequent mortality resulting from thermal stress. Currently, extensive efforts to engage in more holistic research and restoration endeavors have considerably expanded the techniques applied to examine coral samples. Despite such advances, coral bleaching and restoration studies are often conducted within a specific disciplinary focus, where specimens are collected, preserved, and archived in ways that are not always conducive to further downstream analyses by specialists in other disciplines. This approach may prevent the full utilization of unexpended specimens, leading to siloed research, duplicative efforts, unnecessary loss of additional corals to research endeavors, and overall increased costs. A recent US National Science Foundation-sponsored workshop set out to consolidate our collective knowledge across the disciplines of Omics, Physiology, and Microscopy and Imaging regarding the methods used for coral sample collection, preservation, and archiving. Here, we highlight knowledge gaps and propose some simple steps for collecting, preserving, and archiving coral-bleaching specimens that can increase the impact of individual coral bleaching and restoration studies, as well as foster additional analyses and future discoveries through collaboration. Rapid freezing of samples in liquid nitrogen or placing at −80 °C to −20 °C is optimal for most Omics and Physiology studies with a few exceptions; however, freezing samples removes the potential for many Microscopy and Imaging-based analyses due to the alteration of tissue integrity during freezing. For Microscopy and Imaging, samples are best stored in aldehydes. The use of sterile gloves and receptacles during collection supports the downstream analysis of host-associated bacterial and viral communities which are particularly germane to disease and restoration efforts. Across all disciplines, the use of aseptic techniques during collection, preservation, and archiving maximizes the research potential of coral specimens and allows for the greatest number of possible downstream analyses
Molecular Evolution of the Rice Blast Resistance Gene Pi-ta in Invasive Weedy Rice in the USA
The Pi-ta gene in rice has been effectively used to control rice blast disease caused by Magnaporthe oryzae worldwide. Despite a number of studies that reported the Pi-ta gene in domesticated rice and wild species, little is known about how the Pi-ta gene has evolved in US weedy rice, a major weed of rice. To investigate the genome organization of the Pi-ta gene in weedy rice and its relationship to gene flow between cultivated and weedy rice in the US, we analyzed nucleotide sequence variation at the Pi-ta gene and its surrounding 2 Mb region in 156 weedy, domesticated and wild rice relatives. We found that the region at and around the Pi-ta gene shows very low genetic diversity in US weedy rice. The patterns of molecular diversity in weeds are more similar to cultivated rice (indica and aus), which have never been cultivated in the US, rather than the wild rice species, Oryza rufipogon. In addition, the resistant Pi-ta allele (Pi-ta) found in the majority of US weedy rice belongs to the weedy group strawhull awnless (SH), suggesting a single source of origin for Pi-ta. Weeds with Pi-ta were resistant to two M. oryzae races, IC17 and IB49, except for three accessions, suggesting that component(s) required for the Pi-ta mediated resistance may be missing in these accessions. Signatures of flanking sequences of the Pi-ta gene and SSR markers on chromosome 12 suggest that the susceptible pi-ta allele (pi-ta), not Pi-ta, has been introgressed from cultivated to weedy rice by out-crossing
Young off-axis volcanism along the ultraslow-spreading Southwest Indian Ridge
Author Posting. © The Authors, 2010. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Geoscience 3 (2010): 286-292, doi:10.1038/ngeo824.Mid-ocean ridge crustal accretion occurs continuously at all spreading rates
through a combination of magmatic and tectonic processes. Fast to slow spreading
ridges are largely built by adding magma to narrowly focused neovolcanic zones. In
contrast, ultraslow spreading ridge construction significantly relies on tectonic
accretion, which is characterized by thin volcanic crust, emplacement of mantle
peridotite directly to the seafloor, and unique seafloor fabrics with variable
segmentation patterns. While advances in remote imaging have enhanced our
observational understanding of crustal accretion at all spreading rates, temporal
information is required in order to quantitatively understand mid-ocean ridge
construction. However, temporal information does not exist for ultraslow spreading
environments. Here, we utilize U-series eruption ages to investigate crustal
accretion at an ultraslow spreading ridge for the first time. Unexpectedly young
eruption ages throughout the Southwest Indian ridge rift valley indicate that
neovolcanic activity is not confined to the spreading axis, and that magmatic crustal
accretion occurs over a wider zone than at faster spreading ridges. These
observations not only suggest that crustal accretion at ultraslow spreading ridges is
distinct from faster spreading ridges, but also that the magma transport
mechanisms may differ as a function of spreading rate.This work was supported by
the following NSF grants: NSF-OCE 0137325; NSF-OCE 060383800; and NSF-OCE
062705300
A communal catalogue reveals Earth’s multiscale microbial diversity
Our growing awareness of the microbial world’s importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth’s microbial diversity
A communal catalogue reveals Earth's multiscale microbial diversity
Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe
An Active Network Based Design of a QoS Adaptive Video Multicast Service
This paper describes an active network based design of a QoS adaptive video multicast service, called VideoCast, that is overlaid over the existing IP multicast service. VideoCast supports a flexible, receiver-oriented resource allocation scheme that allows a receiver to select a mix of resource reservation and best effort services to be used for the delivery of a video stream. It implements a dynamic QoS control function that isolates video traffic using resource reservations from that using the network's best effort services and dynamically adapts the quality of the video traffic using the latter service to changes in the available bandwidth. By moving the advice about video adaptation into the network, VideoCast overcomes the major challenges faced by existing techniques for video multicast over a best effort network, i.e., difficulty of detecting congestion, latency associated with detecting congestion and reacting to it, and the difficulty of determining when congestion has subsid..