Isolation and amino acid sequence analysis of a 4,000-dalton dynorphin from porcine pituitary

A 4,000-dalton dynorphin was isolated from porcine pituitary. It has 32 amino acids (Mr = 3,986), with the previously described heptadecapeptide (now called dynorphin A) at its amino terminus and a related tridecapeptide, dynorphin B, at its carboxyl terminus. The two peptides are separated by the "processing signal" Lys-Arg

A gas-liquid solid phase peptide and protein sequenator

A new miniaturized protein and peptide sequenator has been constructed which uses gas phase reagents at the coupling and cleavage steps of the Edman degradation. The sample is embedded in a matrix of Polybrene dried onto a porous glass fiber disc located in a small cartridge-style reaction cell. The protein or peptide, though not covalently attached to the support, is essentially immobile throughout the degradative cycle, since only relatively apolar, liquid phase solvents pass through the cell. This instrument can give useful sequence data on as little as 5 pmol or protein, can perform extended sequence runs (greater than 30 residues) on subnanomole quantities of proteins purified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and can sequence hydrophobic peptides to completion. The sequenator is characterized by a high repetitive yield during the degradation, low reagent consumption, low maintenance requirements, and a degradative cycle time of only 50 min using a complete double cleavage program

Fish Distributions and Nutrient Cycling in Streams: Can Fish Create Biogeochemical Hotspots?

Rates of biogeochemical processes often vary widely in space and time, and characterizing this variation is critical for understanding ecosystem functioning. In streams, spatial hotspots of nutrient transformations are generally attributed to physical and microbial processes. Here we examine the potential for heterogeneous distributions of fish to generate hotspots of nutrient recycling. We measured nitrogen (N) and phosphorus (P) excretion rates of 47 species of fish in an N-limited Neotropical stream, and we combined these data with population densities in each of 49 stream channel units to estimate unit- and reach-scale nutrient recycling. Species varied widely in rates of N and P excretion as well as excreted N:P ratios (6–176 molar). At the reach scale, fish excretion could meet \u3e75% of ecosystem demand for dissolved inorganic N and turn over the ambient NH4 pool i

Fish Distributions And Nutrient Cycling In Streams: Can Fish Create Biogeochemical Hotspots

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117137/1/ecy20088982335.pd

Worldwide Diaspora of Aethina tumida (Coleoptera: Nitidulidae), a Nest Parasite of Honey Bees

Native to sub-Saharan Africa, Aethina tumida Murray (Coleoptera: Nitidulidae) is now an invasive pest of honey bee, Apis mellifera L., colonies in Australia and North America. Knowledge about the introduction(s) of this beetle from Africa into and among the current ranges will elucidate pest populations and invasion pathways and contribute to knowledge of how a parasite expands in new populations. We examined genetic variation in adult beetle samples from the United States, Australia, Canada, and Africa by sequencing a 912-base pair region of the mitochondrial DNA cytochrome c oxidase subunit I gene and screening 10 informative microsatellite loci. One Canadian introduction of small hive beetles can be traced to Australia, whereas the second introduction seems to have come from the United States. Beetles now resident in Australia were of a different African origin than were beetles in North America. North American beetles did not show covariance between two mitochondrial haplotypes and their microsatellite frequencies, suggesting that these beetles have a shared source despite having initial genetic structure within their introduced range. Excellent dispersal of beetles, aided in some cases by migratory beekeeping and the bee trade, seems to lead to panmixis in the introduced populations as well as in Afric

Health professionals’ perspectives on delivering home and hospital management at diagnosis for children with type 1 diabetes: a qualitative study from the Delivering Early Care in Diabetes Evaluation (DECIDE) trial

Objective: To explore the delivery of home and hospital management at diagnosis of Type 1 diabetes in childhood and any impact this had on health professionals delivering care. Methods: This qualitative study was undertaken as part of the DECIDE randomised controlled trial where participants were individually randomised to receive initiation of management at diagnosis, to home or hospital. Semi-structured telephone interviews were planned with a purposive sample of health professionals involved with the delivery of home and hospital management, to include consultants, diabetes and research nurses, and dietitians from the eight UK centres taking part. The interview schedule focused on their experiences of delivering the two models of care; preferences, impact and future plans. Data were subject to Thematic Analysis. Results: Twenty two health professionals participated, represented by consultants, diabetes and research nurses, and dietitians. Overall, nurses preferred home management and perceived it to be beneficial in terms of facilitating a unique opportunity to understand family life and provide education to extended family members. Nurses described a special bond and lasting relationship that they developed with the home managed children and families. Consultants expressed concern that it jeopardised their relationship with families. Dietitians reported being unable to deliver short bursts of education to families in the home managed arm. All health professionals were equally divided over which was logistically easier to deliver. Conclusions: A hybrid approach, of a brief stay in hospital and early home management, offers a pragmatic solution to the advantages and challenges presented by both systems

Evolution by Any Other Name: Antibiotic Resistance and Avoidance of the E-Word

The word "evolution" is rarely used in papers from medical journals describing antimicrobial resistance, which may directly impact public perception of the importance of evolutionary biology in our everyday lives

RNA transcripts for I-J polypeptides are apparently not encoded between the I-A and I-E subregions of the murine major histocompatibility complex

The I-J subregion of the mouse major histocompatibility complex has been reported to encode antigenic determinants expressed by suppressor T cells. Previously, cosmid clones were obtained from mouse sperm DNA that contain all of the sequences between the I-A and I-E subregions, where I-J has been mapped genetically. However, hybridization of these sequences to RNA prepared from several I-J-positive suppressor T-cell hybridomas did not reveal the presence of a transcript. In addition, no rearrangements in this DNA were detected in the suppressor T cells that we have analyzed. Our results indicate that the I-J polypeptides are not encoded between the I-A and I-E subregions of the major histocompatibility complex. We discuss several hypotheses concerning the possible location and expression of I-J genes