Environmental,geographical and time-related impacts on avian malaria infections in native and introduced populations of house sparrows (Passer domesticus), a globally invasive species

Aim

The increasing spread of vector-borne diseases has resulted in severe health concerns for humans, domestic animals and wildlife, with changes in land use and the introduction of invasive species being among the main possible causes for this increase. We explored several ecological drivers potentially affecting the local prevalence and richness of avian malaria parasite lineages in native and introduced house sparrows (Passer domesticus) populations.

Location

Global.

Time period

2002–2019.

Major taxa studied

Avian Plasmodium parasites in house sparrows.

Methods

We analysed data from 2,220 samples from 69 localities across all continents, except Antarctica. The influence of environment (urbanization index and human density), geography (altitude, latitude, hemisphere) and time (bird breeding season and years since introduction) were analysed using generalized additive mixed models (GAMMs) and random forests.

Results

Overall, 670 sparrows (30.2%) were infected with 22 Plasmodium lineages. In native populations, parasite prevalence was positively related to urbanization index, with the highest prevalence values in areas with intermediate urbanization levels. Likewise, in introduced populations, prevalence was positively associated with urbanization index; however, higher infection occurred in areas with either extreme high or low levels of urbanization. In introduced populations, the number of parasite lineages increased with altitude and with the years elapsed since the establishment of sparrows in a new locality. Here, after a decline in the number of parasite lineages in the first 30 years, an increase from 40 years onwards was detected.

Main conclusions

Urbanization was related to parasite prevalence in both native and introduced bird populations. In invaded areas, altitude and time since bird introduction were related to the number of Plasmodium lineages found to be infecting sparrows.     

Nanodiamond-promoted white light emission in Eu,Dy, and Cu-containing phosphate glass: quantitative analysis and colorimetric study

A thorough analysis of glass containing Eu₂O₃ and Dy₂O₃, or Eu₂O₃, Dy₂O₃, and CuO melted together with nanodiamond powder was pursued based on measurements of optical absorption, photoluminescence (PL) emission and excitation spectra, and colorimetry. Nanodiamond facilitated the stabilization of Cu⁺ and Eu²⁺ ions with blue-emitting characteristics that, along with yellow-emitting Dy³⁺ and red-emitting Eu³⁺ led to the white light-emitting glass. Novel intensity notations implemented in intensity-based spectral ratios, and difference intensity correlation analysis were proposed for the assessment of PL properties. The chromaticity and correlated colour temperature of the emission were ultimately investigated as a two-parametric problem based on: (1) the different ionic components; and (2) the various excitation wavelengths employed. The optical analysis approach adds to the characterization methods to further fundamental understanding and provide helpful analytical tools for designing materials for tunable white light-emitting devices.     

The α2(XI) collagen gene lies within 8 kb of Pb in the proximal portion of the murine major histocompatibility complex

A number of serious hereditary disorders are now known to be associated with defective expression of collagen genes, and these findings have underscored the important and varied roles that the collagen family of genes must play during normal mammalian development. Although the activities of genes encoding the quantitatively major types of collagen are fairly well characterized, functions of the many minor types of collagen remain a matter of speculation. As a first step toward a functional analysis of type XI collagen, a member of this class of poorly understand minor collagen proteins which is expressed primarily in hyaline cartilage, we have used human probes for the gene encoding the protein's 2-subunit (COL11A2) to isolate and map homologous murine DNA sequences. Our results demonstrate that Col11a-2 is embedded within the major histocompatibility complex (MHC), within 8.4 kb of the class II pseudogene locus, Pb, and confirm that human and murine 2(XI) collagen genes are located in very similar genomic environments. The conserved location of these genes raises the possibility that type XI collagen genes may contribute to one or more of the diverse hereditary disorders known to be linked to the MHC in mouse and human.     

Gross (mesoscopic) and applied anatomy of the anterior inferior cerebellar artery in man with special reference to its course through the cerebellopontine angle region.

In the present paper, we describe anatomical variants of the anterior inferior cerebellar artery in man for applicative purposes. Our goal was to provide the surgeon with a detailed anatomical view of the region. This is similar to what he may observe through the surgical microscope using modern microsurgical techniques. We have focused our attention on the segments of the artery comprising its origin, its course until it reaches the cerebellum and its main collateral branches. Our results confirm the great variability of the elements under study, but enable the establishment of a few basic variational patterns. These patterns together with their relative frequency may be helpful in microsurgery.     

The caecilian amphibian Scolecomorphus kirkii Boulenger as prey of the burrowing asp Atractaspis aterrima Günther: trophic relationships of fossorial vertebrates

A report is given of an adult caecilian, Scolecomorphus kirkii, found in the gut of a specimen of the snake Atractaspis aterrima from the Udzungwa Mountains, Tanzania. Both predator and prey are largely fossorial in soil, and their ecology is poorly known, such that this is the first reported predator of any scolecomorphid caecilian. The caecilian was ingested head first and much of the flesh from the anterior of the specimen had been digested. The prey/predator mass ratio is 0.48. This value is substantially higher than reported for A. aterrima from West Africa, and refutes the notion that this species feeds only on small prey. Most reported predators of caecilians are snakes, and a brief review is presented.     

Production of 6-Phenylacetylene Picolinic Acid from Diphenylacetylene by a Toluene-Degrading Acinetobacter Strain

Several strategies for using enzymes to catalyze reactions leading to the synthesis of relatively simple substituted picolinic acids have been described. The goal of the work described here was to synthesize a more complex molecule, 6-phenylacetylene picolinic acid [6-(2-phenylethynyl)pyridine-2-carboxylic acid], for use as a potential endcapping agent for aerospace polymers. We screened 139 toluene-degrading strains that use a variety of catabolic pathways for the ability to catalyze oxidative transformation of diphenylacetylene. Acinetobacter sp. strain F4 catalyzed the overall conversion of diphenylacetylene to a yellow metabolite, which was identified as a putative meta ring fission product (2-hydroxy-8-phenyl-6-oxoocta-2,4-dien-7-ynoic acid [RFP]). The activity could be sustained by addition of toluene at a flow rate determined empirically so that the transformations were sustained in spite of the fact that toluene is a competitive inhibitor of the enzymes. The overall rate of transformation was limited by the instability of RFP. The RFP was chemically converted to 6-phenylacetylene picolinic acid by treatment with ammonium hydroxide. The results show the potential for using the normal growth substrate to provide energy and to maintain induction of the enzymes involved in biotransformation during preliminary stages of biocatalyst development.     

Recoverability of heat-injured Bacillus spores by lysozyme and EDTA or alkaline thioglycollate

The D_95°C value of Bacillus thuringiensis spores plated in the presence of lysozyme increased from 3.0 min to 3.6 min by post-treatment of heat-injured spores with 50mm EDTA. In the case of Bacillus alvei and Bacillus polymyxa spores D-values decreased from 4.9 to 4.3 min and from 4.7 to 4.1 min respectively. Post-treatment of heat-injured spores treated with alkaline thioglycollate increased D_95°C values of Bacillus alvei from 4.2 to 5.3 min, B. thuringiensis 3.6 to 4.7 min, and Bacillus polymyxa from 4.2 to 5.0 min when spores were plated in the presence of lysozyme. Electron micrographs of heat-injured B. alvei spores treated with sodium thioglycollate indicated that the coat layers of the treated spores were granulated and less intact than the control spores.     

Double blind randomised controlled trial of effect of metoprolol on myocardial ischaemia during endoscopic cholangiopancreatography.

OBJECTIVE--To evaluate the effect of metoprolol, a beta adrenergic blocking drug, on the occurrence of myocardial ischaemia during endoscopic cholangiopancreatography. DESIGN--Double blind, randomised, controlled trial. SETTING--University Hospital. SUBJECTS--38 (two groups of 19) patients scheduled for endoscopic cholangiopancreatography. INTERVENTIONS--Metoprolol 100 mg or placebo as premedication two hours before endoscopy. MAIN OUTCOME MEASURES--Heart rate, arterial oxygen saturation by continuous pulse oximetry, ST segment changes during endoscopic cholangiopancreatography (an ST segment deviation > 1 mV was defined as myocardial ischaemia), electrocardiogram monitored continuously with a Holter tape recorder. RESULTS--All patients had increased heart rate during endoscopy compared with rate before endoscopy, but heart rate during endoscopy was significantly lower in the metoprolol group compared with the placebo group (P = 0.0002). Twenty one patients (16 placebo, 5 metoprolol; P = 0.0008) developed tachycardia (heart rate > 100/min) during the procedure, and 11 patients (10 placebo, 1 metoprolol; P = 0.003) developed myocardial ischaemia. One patient in the placebo group had an acute inferolateral myocardial infarction. In the 10 other patients with signs of myocardial ischaemia during endoscopy the ST deviation disappeared when the endoscope was retracted. In all patients myocardial ischaemia was related to increases in heart rate, and 10 of the 11 patients had tachycardia coherent with myocardial ischaemia. CONCLUSIONS--Metoprolol prevented myocardial ischaemia during endoscopic cholangiopancreatography, probably through lowering the heart rate. Thus, tachycardia seems to be a key pathogenic factor in the development of myocardial ischaemia during endoscopy.