University of Maine

About: University of Maine is a education organization based out in Orono, Maine, United States. It is known for research contribution in the topics: Population & Ice sheet. The organization has 8637 authors who have published 16932 publications receiving 590124 citations. The organization is also known as: University of Maine at Orono.

Candidalysin is a fungal peptide toxin critical for mucosal infection

Abstract: Cytolytic proteins and peptide toxins are classical virulence factors of several bacterial pathogens which disrupt epithelial barrier function, damage cells and activate or modulate host immune responses. Such toxins have not been identified previously in human pathogenic fungi. Here we identify the first, to our knowledge, fungal cytolytic peptide toxin in the opportunistic pathogen Candida albicans. This secreted toxin directly damages epithelial membranes, triggers a danger response signalling pathway and activates epithelial immunity. Membrane permeabilization is enhanced by a positive charge at the carboxy terminus of the peptide, which triggers an inward current concomitant with calcium influx. C. albicans strains lacking this toxin do not activate or damage epithelial cells and are avirulent in animal models of mucosal infection. We propose the name 'Candidalysin' for this cytolytic peptide toxin; a newly identified, critical molecular determinant of epithelial damage and host recognition of the clinically important fungus, C. albicans.

Microbial source tracking markers for detection of fecal contamination in environmental waters: relationships between pathogens and human health outcomes

Abstract: Microbial source tracking (MST) describes a suite of methods and an investigative strategy for determination of fecal pollution sources in environmental waters that rely on the association of certain fecal microorganisms with a particular host. MST is used to assess recreational water quality and associated human health risk, and total maximum daily load allocations. Many methods rely on signature molecules (markers) such as DNA sequences of host-associated microorganisms. Human sewage pollution is among the greatest concerns for human health due to (1) the known risk of exposure to human waste and (2) the public and regulatory will to reduce sewage pollution; however, methods to identify animal sources are receiving increasing attention as our understanding of zoonotic disease potential improves. Here, we review the performance of MST methods in initial reports and field studies, with particular emphasis on quantitative PCR (qPCR). Relationships among human-associated MST markers, fecal indicator bacteria, pathogens, and human health outcomes are presented along with recommendations for future research. An integrated understanding of the advantages and drawbacks of the many MST methods targeting human sources advanced over the past several decades will benefit managers, regulators, researchers, and other users of this rapidly growing area of environmental microbiology.

Resolution of Prochlorococcus and Synechococcus Ecotypes by Using 16S-23S Ribosomal DNA Internal Transcribed Spacer Sequences

Abstract: Cultured isolates of the marine cyanobacteria Prochlorococcus and Synechococcus vary widely in their pigment compositions and growth responses to light and nutrients, yet show greater than 96% identity in their 16S ribosomal DNA (rDNA) sequences. In order to better define the genetic variation that accompanies their physiological diversity, sequences for the 16S-23S rDNA internal transcribed spacer (ITS) region were determined in 32 Prochlorococcus isolates and 25 Synechococcus isolates from around the globe. Each strain examined yielded one ITS sequence that contained two tRNA genes. Dramatic variations in the length and G+C content of the spacer were observed among the strains, particularly among Prochlorococcus strains. Secondary-structure models of the ITS were predicted in order to facilitate alignment of the sequences for phylogenetic analyses. The previously observed division of Prochlorococcus into two ecotypes (called high and low-B/A after their differences in chlorophyll content) were supported, as was the subdivision of the high-B/A ecotype into four genetically distinct clades. ITS-based phylogenies partitioned marine cluster A Synechococcus into six clades, three of which can be associated with a particular phenotype (motility, chromatic adaptation, and lack of phycourobilin). The pattern of sequence divergence within and between clades is suggestive of a mode of evolution driven by adaptive sweeps and implies that each clade represents an ecologically distinct population. Furthermore, many of the clades consist of strains isolated from disparate regions of the world's oceans, implying that they are geographically widely distributed. These results provide further evidence that natural populations of Prochlorococcus and Synechococcus consist of multiple coexisting ecotypes, genetically closely related but physiologically distinct, which may vary in relative abundance with changing environmental conditions.

Forensic Taphonomy : The Postmortem Fate of Human Remains

Abstract: Foreword, J.H. Davis Preface, G. Haynes INTRODUCTION: INTRODUCTION TO FORENSIC TAPHONOMY, W.D. HAGLUND AND M.H. SORG Taphonomy in the Forensic Context Method and Theory of Taphonomic Research, W.D. Haglund and M.H. Sorg Context Delicti: Archaeological Context in Forensic Work, D.D. Scott and M. Connor The Role of Archaeology in the Recovery and Interpretation of Human Remains from an Outdoor Forensic Setting, D.C. Dirkmaat and J.M. Adavasio Chain of Custody from the Field to the Courtroom, J. Melbye and S.B. Jimenez Taphonomic Applications in Forensic Anthropology, D.H. Ubelaker MODIFICATIONS OF SOFT TISSUE, BONE, AND ASSOCIATED MATERIALS: OVERVIEW, W.D. HAGLUND AND M.H. SORG Chemical Underpinnings Chemical and Ultrastructural Aspects of Decomposition, H. Gill-King Preservation and Recovery of DNA in Postmortem Specimens and Trace Samples, T.J. Parsons and V.W. Weedn Soft Tissue The Process of Decomposition: A Model from the Arizona-Sonoran Desert, A. Galloway Postmortem Changes in Soft Tissue, M.A. Clark, M.B. Worrell, and J.E. Pless Recognition of Cemetery Remains in the Forensic Setting, H.E. Berryman, W.M. Bass, S.A. Symes, and O.T. Smith Frozen Environments and Soft Tissue Preservation, M.S. Micozzi Outdoor Decomposition Rates in Tennessee, W.M. Bass, III Bone Microscopic Structure of Bone, M. Schultz Microscopic Investigation of Excavated Skeletal Remains: A Contribution to Paleopathology and Forensic Medicine, M. Schultz A Critical Evaluation of Bone Weathering as an Indication of Bone Assemblage Formation, L.R. Lyman and G.L. Fox Eskimo Skeleton Taphonomy with Identification of Possible Polar Bear Victims, C.F. Merbs Human Variables in the Postmortem Alteration of Human Bone: Examples from U.S. War Casualties, T.D. Holland, B.E. Anderson, and R.W. Mann Fire Modification of Bone: A Review of the Literature, P.M. Mayne Correia Human Bone Mineral Densities and Survival of Bone Elements: A Contemporary Sample, A. Galloway, P. Willey, and L. Snyder Cranial Bone Displacement as a Taphonomic Process in Potential Child Abuse Cases, T.A.J. Crist, A. Washburn, H. Park, I. Hood, and M.A. Hickey Associated Materials Biodegradation of Hair and Fibers, W.F. Rowe Forensic Botany, D. Hall SCAVENGED REMAINS: OVERVIEW, W.D. HAGLUND AND M.H. SORG Carnivore Scavenged Remains Dogs and Coyotes: Postmortem Involvement with Human Remains, W.D. Haglund Scattered Skeletal Remains: Search Strategy Considerations for Locating Missing Teeth, W.D. Haglund The Utilization of Faunal Evidence in the Recovery of Human Remains, T.A. Murad Rodent Scavenged Remains Rodents and Human Remains, W.D. Haglund Scavenging by Insects On the Body: Insects' Life Stage Presence, Their Postmortem Artifacts, and Entomological Collecting Procedures, N.H. Haskell, V.J. Cervenka, and M.A. Clark Scavenging by Water Organisms Human Remains Recovered from a Shark's Stomach in South Carolina, T.A. Rathbun and B.C. Rathbun BURIED AND PROTECTED REMAINS: OVERVIEW, W.D. HAGLUND AND M.H. SORG Decomposition Decomposition of Buried and Submerged Bodies, W.C. Rodriguez III Decomposition Rates of Deliberate Burials: A Case Study of Preservation, M.H. Manheim Autopsied, Embalmed, and Preserved Human Remains: Distinguishing Features in Forensic and Historic Contexts, P.S. Sledzik and M.S. Micozzi Necrosearch Revisited: Further Multidisciplinary Approaches to the Detection of Clandestine Graves, D.L. France, T.J. Griffin, J.G. Swanburg, J.W. Lindemann, G.C. Davenport, V. Trammell, C.T. Travis, B. Kondratieff, A. Nelson, K. Castellano, D. Hopkins, and T. Adair Preservation in Late 19th Century Iron Coffin Burials, D.W. Owsley and B.E. Compton REMAINS IN WATER: OVERVIEW, W.D. HAGLUND AND M.H. SORG Riverine Environments Fluvial Transport of Human Crania, S.P. Nawrocki, J.E. Pless, D.A. Hawley, and S.A. Wagner The Taphonomic Effects of Flood Waters on Bone, S. Brooks and R.H. Brooks Lacustrine Environments Movement of Bodies in Lake Ontario, Tyler G. O'Brien Marine Environments Forensic Taphonomy in Marine Contexts, M.H. Sorg, J.H. Dearborn, E.I. Monahan, H.F. Ryan, K.G. Sweeney, and E. David Human Aquatic Taphonomy in the Monterey Bay Area, S. Boyle, A. Galloway, and R.T. Mason Burials at Sea, M.R. London, J.F. Krolikowski, and J.H. Davis CONCLUSIONS AND OVERVIEW, W.D. HAGLUND AND M.H. SORG Afterword, C.C. Snow