• First comparison of LSU rDNA copy numbers in A. catenella cysts and vegetative cells across regions and seasons. • Regionally, cyst and vegetative cell rDNA copy numbers did not significantly differ. • Sampling period was a significant predictor of cyst rDNA copy number. • A. catenella rDNA copies ranged from ∼200-2500 copies per cell. • Cyst abundance estimates were consistent between standard microscopy and qPCR methods and qPCR methods were an efficient approach for quantifying cysts, particularly for large surveys. Alexandrium catenella is one of many cyst-forming Alexandrium harmful algal bloom species (HABs) that cause paralytic shellfish poisoning. Identifying and quantifying A. catenella cysts from environmental samples using microscopy is time-consuming and challenging due to their shared morphological similarities with other cysts. In this study, we used molecular methods to increase efficiency of quantifying cysts from environmental samples by employing a qPCR assay that targeted the LSU ribosomal gene. To optimize cyst quantification, we made a regional, seasonal, and life cycle stage investigation of A. catenella rDNA copy number content. To our knowledge, this is the first study to make such a comparison. Our experimental design included A. catenella vegetative strains and cysts collected from the Gulf of Maine (GOM), Kodiak Island, Alaska, and Puget Sound, Washington. The results revealed that there were no significant differences regionally in rDNA copy numbers between cysts and vegetative cells, however, sampling period was a significant predictor of cyst rDNA copy number. The validity of using the qPCR assay for making cyst abundance estimates was confirmed by comparing qPCR estimates to microscopic counts in sediment samples collected during NOAA A. catenella cyst surveys in the GOM. The application of qPCR methods instead of manual counting to enumerate cysts is recommended as an efficient, cost effective, and time saving approach for monitoring cyst abundances, particularly for large surveys. The results of this study have implications for molecular quantification of not only A. catenella , but also other HAB species with similar life cycle strategies. [ABSTRACT FROM AUTHOR]

In the scope of the development of a microarray PhyloChip for the detection of toxic phytoplankton species, we designed a large series of probes specific against targets in the nuclear large subunit (LSU) rRNA of a range of Pseudo-nitzschia species and spotted these onto the microarray. Hybridisation with rRNA extracted from monoclonal cultures and from plankton samples revealed many cross-reactions. In the present work, we tested the functionality and specificity of 23 of these probes designed against ten of the species, using a dot-blot procedure. In this case, probe specificity is tested against the target region in PCR products of the LSU rRNA gene marker region blotted on nitrocellulose filters. Each filter was incubated with a species-specific oligoprobe. Eleven of the tested probes showed specific responses, identifying seven Pseudo-nitzschia species. The other probes showed non-specific responses or did not respond at all. Results of dot-blot hybridisations are more specific than those obtained with the microarray approach and the possible reasons for this are discussed.

No summary available.

The integration of low Earth orbit (LEO) satellites and unmanned aerial vehicles (UAVs) into the maritime Internet of Things (MIoT) offers an effective solution to overcoming the limitations of connectivity and transmission reliability in conventional MIoT, thereby supporting marine data acquisition. However, the highly dynamic ocean environment necessitates a theoretical framework for system-level performance evaluation before practical deployment. In this article, we consider a LEO satellite and UAV-assisted MIoT (LSU-MIoT) network and develop an analytical framework to evaluate its transmission performance. Specifically, marine devices and relaying buoys are modeled as a Matérn cluster process on the sea surface, UAVs as a homogeneous Poisson point process, and LEO satellites as a spherical Poisson point process. Signal transmissions over marine, aerial, and space links are characterized by Nakagami-m, Rician, and shadowed Rician fading, respectively, with the two-ray path loss model applied to sea and air links for accurately capturing propagation characteristics. By leveraging stochastic geometry, we derive analytical expressions for transmission success probability and end-to-end delay of regular and emergency data under the time division multiple access and non-orthogonal multiple access schemes. Simulation results validate the accuracy of derived expressions and reveal the impact of key parameters on the performance of LSU-MIoT networks. [ABSTRACT FROM AUTHOR]

Center for Advanced Microstructures and Devices of Louisiana State University (LSU CAMD) is a research center for optimization of synchrotron radiation (SR) for production of soft X-rays. New research projects have necessitated expansion of the SR spectral range to harder X-rays. This task was solved via installation of a superconducting insertion device. This paper presents a description of the superconducting wiggler with a field of 7.5 T made by Budker INP and installed on the storage ring of LSU CAMD. The wiggler consists of 11 main bending magnets with magnetic field with alternating sign and an amplitude of 7.5 T and four side poles (two on each end of the magnet array), which are to make the first and second field integrals in the longitudinal direction equal to zero at any field level of the main poles. The main attention at the designing and production of the magnetic system of the wiggler was paid to the magnetic field quality at all field levels. Presented are results of field magnetic measurements using Hall probes. The dynamic behavior of the first and second field integrals during field ramping up and down, as measured by the method of stretched wire with current, is discussed. The wiggler was installed and successfully commissioned on the CAMD LSU storage ring in 2013.

This case study chronicles the impact of Hurricane Katrina on the Department of Radiology at the Louisiana State University School of Medicine in New Orleans and the department's subsequent efforts to recover and re-dedicate itself to providing quality patient care and resident education. Hurricane Katrina damaged the department's facilities, severely decreased departmental cash flow, disrupted resident education, and resulted in faculty exodus. Because of the “catastrophic loss of resources” suffered by the department, the Accreditation Council for Graduate Medical Education (ACGME) proposed expedited withdrawal of accreditation for the Diagnostic Radiology Residency Program, to which the department agreed. Since Katrina, the program has taken steps toward regaining its pre-Katrina status as a successful residency program that produced satisfied, successful residents. These steps include the appointment of a new department head of radiology, the recruitment of academic directors for each of the nine subspecialties, the reopening of the University Hospital, and the growth of annual procedure volume. All institutions face the possibility of a natural disaster. It is imperative to have a plan in place to ensure continued resident education, patient safety, and ACGME accreditation.