Tropical Atlantic sea level variability from Geosat (1985-1989)

Geosat altimeter data between april 1985 and september 1989 are analyzed in the Tropical Atlantic ocean. First, improvements due to the use of new corrections and orbit computations are found to be effective, especially in the Gulf of Guinea, where part of the previously missing signal is recovered. Then, the variability of the ocean is examined using empirical orthogonal functions (EOFs). Only three EOFs are needed to describe 80% of the seasonal variance. The first one describes the meridional tilting of the Tropical Atlantic along the mean location of the Intertropical Convergence Zone, with an annual period. The second describes a mass redistribution due to the equatorial upwelling peaking in June-July. The third function presents semiannual signal. Looking at interannual variability, the first EOF reveals a mass redistribution between the Equatorial region (10°N to 10°S) and the Northern and Southern ones (10°N to 30°N, 10°S to 30°S°). In the Equatorial region the upper layer volume increases .... between 1987 and 1989. Occurring 1 year after the Pacific EL Nino, this phenomenon recalls the 1984 anomaly observed during the "Programme Français Océan et Climat en Atlantique Tropical"/Seasonal Equatorial Atlantic experiments. (Résumé d'auteur

Single cell analysis of nutrient regulation of Clostridioides (Clostridium) difficile motility

Regulation of bacterial motility to maximize nutrient acquisition or minimize exposure to harmful substances plays an important role in microbial proliferation and host colonization. The technical difficulties of performing high-resolution live microscopy on anaerobes have hindered mechanistic studies of motility in Clostridioides (formerly Clostridium) difficile. Here, we present a widely applicable protocol for live cell imaging of anaerobic bacteria that has allowed us to characterize C. difficile swimming at the single-cell level. This accessible method for anaerobic live cell microscopy enables inquiry into previously inaccessible aspects of C. difficile physiology and behavior. We present the first report that vegetative C. difficile are capable of regulated motility in the presence of different nutrients. We demonstrate that the epidemic C. difficile strain R20291 exhibits regulated motility in the presence of multiple nutrient sources by modulating its swimming velocity. This is a powerful illustration of the ability of single-cell studies to explain population-wide phenomena such as dispersal through the environment

A novel 65 kDa RNA-binding protein in squid presynaptic terminals

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Neuroscience 166 (2010): 73-83, doi:10.1016/j.neuroscience.2009.12.005.A polyclonal antibody (C4), raised against the head domain of chicken myosin Va, reacted strongly towards a 65 kDa polypeptide (p65) on western blots of extracts from squid optic lobes but did not recognize the heavy chain of squid myosin V. This peptide was not recognized by other myosin Va antibodies, nor by an antibody specific for squid myosin V. In an attempt to identify it, p65 was purified from optic lobes of Loligo plei by cationic exchange and reverse phase chromatography. Several peptide sequences were obtained by mass spectroscopy from p65 cut from SDS-PAGE gels. BLAST analysis and partial matching with ESTs from a Loligo pealei data bank indicated that p65 contains consensus signatures for the hnRNP A/B family of RNA-binding proteins. Centrifugation of post mitochondrial extracts from optic lobes on sucrose gradients after treatment with RNase gave biochemical evidence that p65 associates with cytoplasmic RNP complexes in an RNA-dependent manner. Immunohistochemistry and immunofluorescence studies using the C4 antibody showed partial co-labeling with an antibody against squid synaptotagmin in bands within the outer plexiform layer of the optic lobes and at the presynaptic zone of the stellate ganglion. Also, punctate labeling by the C4 antibody was observed within isolated optic lobe synaptosomes. The data indicate that p65 is a novel RNA-binding protein located to the presynaptic terminal within squid neurons and may have a role in synaptic localization of RNA and its translation or processing.REL, JCR and JEM received financial support from the Fundação de Amparo à Pesquisa do Estado de Sao Paulo (FAPESP), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and the Fundação de Apoio ao Ensino, Pesquisa e Assistência do Hospital das Clínicas da FMRP-USP (FAEPA). JAD received financial support from the RI-INBRE Program Grant #P20RR016457 from the Nation Center for Research Resources, NIH, Bethesda, MD. DTPL, LC, SBFT, EJRV and MMAB were recipients of research fellowships from FAPESP and CNPq. REL and JEM received Productivityin- Research fellowships from CNPq

Content and performance of the MiniMUGA genotyping array: A new tool to improve rigor and reproducibility in mouse research

The laboratory mouse is the most widely used animal model for biomedical research, due in part to its well-annotated genome, wealth of genetic resources, and the ability to precisely manipulate its genome. Despite the importance of genetics for mouse research, genetic quality control (QC) is not standardized, in part due to the lack of cost-effective, informative, and robust platforms. Genotyping arrays are standard tools for mouse research and remain an attractive alternative even in the era of high-throughput whole-genome sequencing. Here, we describe the content and performance of a new iteration of the Mouse Universal Genotyping Array (MUGA), MiniMUGA, an array-based genetic QC platform with over 11,000 probes. In addition to robust discrimination between most classical and wild-derived laboratory strains, MiniMUGA was designed to contain features not available in other platforms: (1) chromosomal sex determination, (2) discrimination between substrains from multiple commercial vendors, (3) diagnostic SNPs for popular laboratory strains, (4) detection of constructs used in genetically engineered mice, and (5) an easy-to-interpret report summarizing these results. In-depth annotation of all probes should facilitate custom analyses by individual researchers. To determine the performance of MiniMUGA, we genotyped 6899 samples from a wide variety of genetic backgrounds. The performance of MiniMUGA compares favorably with three previous iterations of the MUGA family of arrays, both in discrimination capabilities and robustness. We have generated publicly available consensus genotypes for 241 inbred strains including classical, wild-derived, and recombinant inbred lines. Here, we also report the detection of a substantial number of XO and XXY individuals across a variety of sample types, new markers that expand the utility of reduced complexity crosses to genetic backgrounds other than C57BL/6, and the robust detection of 17 genetic constructs. We provide preliminary evidence that the array can be used to identify both partial sex chromosome duplication and mosaicism, and that diagnostic SNPs can be used to determine how long inbred mice have been bred independently from the relevant main stock. We conclude that MiniMUGA is a valuable platform for genetic QC, and an important new tool to increase the rigor and reproducibility of mouse research

Tropical Atlantic sea level variability from Geosat (1985-1989)

Geosat altimeter data between april 1985 and september 1989 are analyzed in the Tropical Atlantic ocean. First, improvements due to the use of new corrections and orbit computations are found to be effective, especially in the Gulf of Guinea, where part of the previously missing signal is recovered. Then, the variability of the ocean is examined using empirical orthogonal functions (EOFs). Only three EOFs are needed to describe 80% of the seasonal variance. The first one describes the meridional tilting of the Tropical Atlantic along the mean location of the Intertropical Convergence Zone, with an annual period. The second describes a mass redistribution due to the equatorial upwelling peaking in June-July. The third function presents semiannual signal. Looking at interannual variability, the first EOF reveals a mass redistribution between the Equatorial region (10°N to 10°S) and the Northern and Southern ones (10°N to 30°N, 10°S to 30°S°). In the Equatorial region the upper layer volume increases .... between 1987 and 1989. Occurring 1 year after the Pacific EL Nino, this phenomenon recalls the 1984 anomaly observed during the "Programme Français Océan et Climat en Atlantique Tropical"/Seasonal Equatorial Atlantic experiments. (Résumé d'auteur