53 research outputs found
Application and Validation of PFGE for Serovar Identification of Leptospira Clinical Isolates
Serovar identification of clinical isolates of Leptospira is generally not performed on a routine basis, yet the identity of an infecting serovar is valuable from both epidemiologic and public health standpoints. Only a small number of reference laboratories worldwide have the capability to perform the cross agglutinin absorption test (CAAT), the reference method for serovar identification. Pulsed-field gel electrophoresis (PFGE) is an alternative method to CAAT that facilitates rapid identification of leptospires to the serovar level. We employed PFGE to evaluate 175 isolates obtained from humans and animals submitted to the Centers for Disease Control and Prevention (CDC) between 1993 and 2007. PFGE patterns for each isolate were generated using the NotI restriction enzyme and compared to a reference database consisting of more than 200 reference strains. Of the 175 clinical isolates evaluated, 136 (78%) were identified to the serovar level by the database, and an additional 27 isolates (15%) have been identified as probable new serovars. The remaining isolates yet to be identified are either not represented in the database or require further study to determine whether or not they also represent new serovars. PFGE proved to be a useful tool for serovar identification of clinical isolates of known serovars from different geographic regions and a variety of different hosts and for recognizing potential new serovars
The intertropical convergence zone modulates intense hurricane strikes on the western North Atlantic margin
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 6 (2016): 21728, doi:10.1038/srep21728Most Atlantic hurricanes form in the Main Development Region between 9°N to 20°N along the northern edge of the Intertropical Convergence Zone (ITCZ). Previous research has suggested that meridional shifts in the ITCZ position on geologic timescales can modulate hurricane activity, but continuous and long-term storm records are needed from multiple sites to assess this hypothesis. Here we present a 3000 year record of intense hurricane strikes in the northern Bahamas (Abaco Island) based on overwash deposits in a coastal sinkhole, which indicates that the ITCZ has likely helped modulate intense hurricane strikes on the western North Atlantic margin on millennial to centennial-scales. The new reconstruction closely matches a previous reconstruction from Puerto Rico, and documents a period of elevated intense hurricane activity on the western North Atlantic margin from 2500 to 1000 years ago when paleo precipitation proxies suggest that the ITCZ occupied a more northern position. Considering that anthropogenic warming is predicted to be focused in the northern hemisphere in the coming century, these results provide a prehistoric analog that an attendant northern ITCZ shift in the future may again return the western North Atlantic margin to an active hurricane interval.This research was supported by NSF Awards: OCE-1519578, OCE-1356708, BCS-1118340
Coupled atmosphere–mixed layer ocean response to ocean heat flux convergence along the Kuroshio Current Extension
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Climate Dynamics 36 (2011): 2295-2312, doi:10.1007/s00382-010-0764-8.The winter response of the coupled atmosphere-ocean mixed layer system to
anomalous geostrophic ocean heat flux convergence in the Kuroshio Extension is
investigated by means of experiments with an atmospheric general circulation model
coupled to an entraining ocean mixed layer model in the extra-tropics. The direct
response consists of positive SST anomalies along the Kuroshio Extension and a
baroclinic (low-level trough and upper-level ridge) circulation anomaly over the North
Pacific. The low-level component of this atmospheric circulation response is weaker in
the case without coupling to an extratropical ocean mixed layer, especially in late winter.
The inclusion of an interactive mixed layer in the tropics modifies the direct coupled
atmospheric response due to a northward displacement of the Pacific Inter-Tropical
Convergence Zone which drives an equivalent barotropic anomalous ridge over the North
Pacific. Although the tropically-driven component of the North Pacific atmospheric
circulation response is comparable to the direct response in terms of sea level pressure
amplitude, it is less important in terms of wind stress curl amplitude due to the mitigating
effect of the relatively broad spatial scale of the tropically-forced atmospheric
teleconnection.We gratefully acknowledge
financial support from NOAA’s Office of Global Programs (grant to C. Deser and Y.-O.
Kwon). Y.-O. Kwon is also supported through the Claudia Heyman Fellowship of the
WHOI Ocean Climate Change Institute
Seasonal and decadal forecasts of Atlantic Sea surface temperatures using a linear inverse model
Modulation of the Pacific Decadal Oscillation on the summer precipitation over East China: a comparison of observations to 600-years control run of Bergen Climate Model
Understanding the control of extratropical atmospheric variability on ENSO using a coupled data assimilation approach
The influence of boreal winter extratropical North Pacific Oscillation on Australian spring rainfall
Siberian high variability and its teleconnections with tropical circulations and surface air temperature over Saudi Arabia
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