Using priority to food access: fattening strategies in dominance-structured willow tit (Parus montanus) flocks

We studied changes in body mass in response to priority to foodaccess by repeatedly weighing free-living willow tits in dominance-structuredflocks. Priority to food access did not correlate to eitheracquisition rate or net turnover of body reserves, but subordinateswith low food availability had larger body reserves than dominants.Removal experiments suggest a causal relationship between rankand the size of reserves. Body reserves of subordinates decreasedwhen their access to food increased after the dominant was removed.Low variability in body mass of subordinates shows that theydo not maintain large reserves in response to uncertain acquisitionof food. Rather, large reserves of low-rank individuals couldserve as insurance for conditions with increasing requirements.Under such conditions, dominants are more likely to claim theirpriority to food, and subordinates would not be able to increasetheir body reserves by feeding.     

Simultaneous mutations in CA and Vif of Maedi-Visna virus cause attenuated replication in macrophages and reduced infectivity in vivo

Maedi-visna virus (MVV) is a lentivirus of sheep sharing several key features with the primate lentiviruses. The virus causes slowly progressive diseases, mainly in the lungs and the central nervous system of sheep. Here, we investigate the molecular basis for the differential growth phenotypes of two MVV isolates. One of the isolates, KV1772, replicates well in a number of cell lines and is highly pathogenic in sheep. The second isolate, KS1, no longer grows on macrophages or causes disease. The two virus isolates differ by 129 nucleotide substitutions and two deletions of 3 and 15 nucleotides in the env gene. To determine the molecular nature of the lesions responsible for the restrictive growth phenotype, chimeric viruses were constructed and used to map the phenotype. An L120R mutation in the CA domain, together with a P205S mutation in Vif (but neither alone), could fully convert KV1772 to the restrictive growth phenotype. These results suggest a functional interaction between CA and Vif in MVV replication, a property that may relate to the innate antiretroviral defense mechanisms in sheep.     

Isolation and identification of antimicrobial components from the epidermal mucus of Atlantic cod (Gadus morhua)

The epidermal mucus of fish species has been found to contain antimicrobial proteins and peptides, which is of interest in regard to fish immunity. An acidic extract from the epidermal mucus of the Atlantic cod (Gadus morhua) was found to exhibit antimicrobial activity against Bacillus megaterium, Escherichia coli and Candida albicans. This activity varied significantly when salt was added to the antimicrobial assay, and was eliminated by pepsin digestion. No lysozyme activity was detected in the extract. By using weak cationic exchange chromatography together with reversed-phase chromatography, and monitoring the antimicrobial activity, we have isolated four cationic proteins from the mucus extract. Using N-terminal and C-terminal amino acid sequence analysis, together with MS, the antimicrobial proteins were identified as histone H2B (13 565 Da), ribosomal protein L40 (6397 Da), ribosomal protein L36A (12 340 Da) and ribosomal protein L35 (14 215 Da). The broad spectra of antimicrobial activities in the cod mucus and the characterization of four antimicrobial polypeptides suggest that mucus compounds contribute to the innate host defence of cod.     

Biodiversity gradient in the Baltic Sea: a comprehensive inventory of macrozoobenthos data

In the Helsinki Commission Red List project 2009–2012, taxonomic and distributional data of benthic (macro) invertebrates were compiled by the present authors in a comprehensive checklist of the Baltic Sea fauna. Based on the most recent and comprehensive data, this paper presents the diversity patterns observed among benthic invertebrates in the Baltic Sea. As expected, the total number of species per sub-region generally declined along the salinity gradient from the Danish Straits to the northern Baltic Sea. This relationship is well known from the Baltic Sea and has resulted in a general assumption of an exponentially positive relationship between species richness and salinity for marine species, and a negative relationship for freshwater species. In 1934, Remane produced a diagram to describe the hypothetical distribution of benthic invertebrate diversity along a marine–freshwater salinity gradient. Our results clearly indicated the validity of this theory for the macrozoobenthic diversity pattern within the Baltic Sea. Categorisation of sub-regions according to species composition showed both separation and grouping of some sub-regions and a strong alignment of similarity patterns of zoobenthic species composition along the salinity gradient.     

Incidence and outcome of acute phosphate nephropathy in Iceland

Background

Oral sodium phosphate solutions (OSPS) are widely used for bowel cleansing prior to colonoscopy and other procedures. Cases of renal failure due to acute phosphate nephropathy following OSPS ingestion have been documented in recent years, questioning the safety of OSPS. However, the magnitude of the problem remains unknown.

Methodology/Principal Findings

We conducted a population based, retrospective analysis of medical records and biopsies of all cases of acute phosphate nephropathy that were diagnosed in our country in the period from January 2005 to October 2008. Utilizing the complete official sales figures of OSPS, we calculated the incidence of acute phosphate nephropathy in our country. Fifteen cases of acute phosphate nephropathy were diagnosed per 17,651 sold doses of OSPS (0.085%). Nine (60%) were women and mean age 69 years (range 56–75 years). Thirteen patients had a history of hypertension (87%) all of whom were treated with either ACE-I or ARB and/or diuretics. One patient had underlying DM type I and an active colitis and one patient had no risk factor for the development of acute phosphate nephropathy. Average baseline creatinine was 81.7 µmol/L and 180.1 at the discovery of acute renal failure, mean 4.2 months after OSPS ingestion. No patient had a full recovery of renal function, and at the end of follow-up, 26.6 months after the OSPS ingestion, the average creatinine was 184.2 µmol/L. The average eGFR declined from 73.5 ml/min/1.73 m² at baseline to 37.3 ml/min/1.73 m² at the end of follow-up. One patient reached end-stage renal disease and one patient died with progressive renal failure.

Conclusion/Significance

Acute phosphate nephropathy developed in almost one out of thousand sold doses of OSPS. The consequences for kidney function were detrimental. This information can be used in other populations to estimate the impact of OSPS. Our data suggest that acute phosphate nephropathy may be greatly underreported worldwide.     

Two-dimensional strandness-dependent electrophoresis

Two-dimensional strandness-dependent electrophoresis (2D-SDE) separates nucleic acids in complex samples according to strandness, conformation and length. Under the non-denaturing conditions of the first electrophoretic step, single-stranded DNA, double-stranded DNA and RNA.DNA hybrids of similar length migrate at different rates. The second electrophoretic step is performed under denaturing conditions (7 mol l(-1) urea, 55 degrees C) so that all the molecules are single-stranded and separate according to length only. 2D-SDE is useful for revealing important characteristics of complex nucleic acid samples in manipulations such as amplification, renaturation, cDNA synthesis and microarray hybridization. It can also be used to identify mispaired, nicked or damaged fragments in double-stranded DNA. The protocol takes approximately 2 h and requires only basic skills, equipment and reagents.