Richard W. Merritt

Bio: Richard W. Merritt is an academic researcher from Michigan State University. The author has contributed to research in topics: Mycobacterium ulcerans & Buruli ulcer. The author has an hindex of 44, co-authored 129 publications receiving 13068 citations.

An introduction to the aquatic insects of north america

Abstract: an introduction coweeta lter an introduction to the aquatic insects of north america an introduction to the aquatic insects of north america (size 63,76mb) epub an introduction to the aquatic insects an introduction to the aquatic insects of north america syllabus aquatic insects of north amerca spring 2014 (size 24,70mb) epub download an introduction to the freshwater macroinvertebrates of ny (filesize 19,71mb) kindle an introduction to the aquatic aquatic insects wisconsin department of natural resources an introduction to the aquatic insects of north america “aquatic entomology” university of maryland college aquatic insects bspm 445 fall 2012 aquatic insects instructor current: jun 2009 : volume 28 issue 2 biting aquatic bugs.ppt university of florida phc 6937: water biology aquatic insects atlas of the dragonfly larvae wildlife home aquatic insects some general information about north bsc 492/648: aquatic insect ecology yee, spring 2012 dichotomous key for insects clemson university taxonomic references georgia atlas of the aquatic and semiaquatic true bugs biological monitoring aquatic macroinvertebrate the techniques of water-resources investigations of the united introduction to insects filesmpusblogs this key has been reproduced from brigham, brigham and book review university of chicago press factors associated with bluegill nest site selection richard w. merritt, kenneth w. cummins y martin b. berg aquatic moths colorado parks and wildlife stream ecosystem structure: aquatic macroinvertebrate ecology and classi? cation of north american freshwater a database of lotic invertebrate traits for north america identification and reference materials texas tceq aquatic insects of india-a fieldguide aquatic insects bspm 445 aquatic insects instructor: b.c publications: glenn b. wiggins, curator emeritus, entomology redalycseña de 'an introduction to the aquatic insects an introduction to the aquatic insects of north america

The use of invertebrate functional groups to characterize ecosystem attributes in selected streams and rivers in south Brazil

Abstract: An analysis conducted at nine stream/river sites in the Atlantic Forest region in the State of Parana, Brazil used macroinvertebrate functional feeding group (FFG) assessments to evaluate ecological condition of the sites. The FFG approach categorizes qualitative macroinvertebrate collections according to their morphological-behavioral adaptations for food acquisition (e.g. scrapers that harvest non-filamentous, attached algae from stable surfaces in flowing water). FFG ratios were employed as surrogates for stream/river ecosystem attributes: balance between autotrophy and heterotrophy; linkage between riparian inputs of coarse particulate organic matter and in-stream food webs; relative dominance of fine particulate organic matter in transport (suspended load) compared to that deposited in the sediments; and geomorphic stability of the channel. The analyses indicated that all nine sites were heterotrophic, six of the nine carried expected levels of suspended organic load and showed below expected linkage...

Ecology and transmission of Buruli ulcer disease: a systematic review.

Abstract: Buruli ulcer is a neglected emerging disease that has recently been reported in some countries as the second most frequent mycobacterial disease in humans after tuberculosis. Cases have been reported from at least 32 countries in Africa (mainly west), Australia, Southeast Asia, China, Central and South America, and the Western Pacific. Large lesions often result in scarring, contractual deformities, amputations, and disabilities, and in Africa, most cases of the disease occur in children between the ages of 4–15 years. This environmental mycobacterium, Mycobacterium ulcerans, is found in communities associated with rivers, swamps, wetlands, and human-linked changes in the aquatic environment, particularly those created as a result of environmental disturbance such as deforestation, dam construction, and agriculture. Buruli ulcer disease is often referred to as the “mysterious disease” because the mode of transmission remains unclear, although several hypotheses have been proposed. The above review reveals that various routes of transmission may occur, varying amongst epidemiological setting and geographic region, and that there may be some role for living agents as reservoirs and as vectors of M. ulcerans, in particular aquatic insects, adult mosquitoes or other biting arthropods. We discuss traditional and non-traditional methods for indicting the roles of living agents as biologically significant reservoirs and/or vectors of pathogens, and suggest an intellectual framework for establishing criteria for transmission. The application of these criteria to the transmission of M. ulcerans presents a significant challenge.

Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection.

Abstract: We have systematically made a set of precisely defined, single-gene deletions of all nonessential genes in Escherichia coli K-12. Open-reading frame coding regions were replaced with a kanamycin cassette flanked by FLP recognition target sites by using a one-step method for inactivation of chromosomal genes and primers designed to create in-frame deletions upon excision of the resistance cassette. Of 4288 genes targeted, mutants were obtained for 3985. To alleviate problems encountered in high-throughput studies, two independent mutants were saved for every deleted gene. These mutants-the 'Keio collection'-provide a new resource not only for systematic analyses of unknown gene functions and gene regulatory networks but also for genome-wide testing of mutational effects in a common strain background, E. coli K-12 BW25113. We were unable to disrupt 303 genes, including 37 of unknown function, which are candidates for essential genes. Distribution is being handled via GenoBase (http://ecoli.aist-nara.ac.jp/).

Landscapes and Riverscapes: The Influence of Land Use on Stream Ecosystems

Abstract: ▪ Abstract Local habitat and biological diversity of streams and rivers are strongly influenced by landform and land use within the surrounding valley at multiple scales. However, empirical associations between land use and stream response only varyingly succeed in implicating pathways of influence. This is the case for a number of reasons, including (a) covariation of anthropogenic and natural gradients in the landscape; (b) the existence of multiple, scale-dependent mechanisms; (c) nonlinear responses; and (d) the difficulties of separating present-day from historical influences. Further research is needed that examines responses to land use under different management strategies and that employs response variables that have greater diagnostic value than many of the aggregated measures in current use. In every respect, the valley rules the stream. H.B.N. Hynes (1975)

Microbial Biofilms: from Ecology to Molecular Genetics

Abstract: Biofilms are complex communities of microorganisms attached to surfaces or associated with interfaces. Despite the focus of modern microbiology research on pure culture, planktonic (free-swimming) bacteria, it is now widely recognized that most bacteria found in natural, clinical, and industrial settings persist in association with surfaces. Furthermore, these microbial communities are often composed of multiple species that interact with each other and their environment. The determination of biofilm architecture, particularly the spatial arrangement of microcolonies (clusters of cells) relative to one another, has profound implications for the function of these complex communities. Numerous new experimental approaches and methodologies have been developed in order to explore metabolic interactions, phylogenetic groupings, and competition among members of the biofilm. To complement this broad view of biofilm ecology, individual organisms have been studied using molecular genetics in order to identify the genes required for biofilm development and to dissect the regulatory pathways that control the plankton-to-biofilm transition. These molecular genetic studies have led to the emergence of the concept of biofilm formation as a novel system for the study of bacterial development. The recent explosion in the field of biofilm research has led to exciting progress in the development of new technologies for studying these communities, advanced our understanding of the ecological significance of surface-attached bacteria, and provided new insights into the molecular genetic basis of biofilm development.

X-Ray Diffraction

Abstract: Interpretation of X-ray Powder Diffraction Patterns . By H. Lipson and H. Steeple. Pp. viii + 335 + 3 plates. (Mac-millan: London; St Martins Press: New York, May 1970.) £4.