A comprehensive molecular phylogeny of Afrotropical white-eyes (Aves: Zosteropidae) highlights prior underestimation of mainland diversity and complex colonisation history

White-eyes (Zosterops) are a hyper-diverse genus of passerine birds that have rapidly radiated across the Afrotropics and Southeast Asia. Despite their broad range, a disproportionately large number of species are currently recognised from islands compared to the mainland. Described species-level diversity of this ‘great speciator’ from continental Africa-Arabia is strikingly low, despite the vast size and environmental complexity of this region. However, efforts to identify natural groups using traditional approaches have been hindered by the remarkably uniform morphology and plumage of these birds. Here, we investigated the phylogenetic relationships and systematics of Afrotropical Zosterops, including the Gulf of Guinea and western Indian Ocean islands. We included exceptional sampling (∼160 individuals) from all except one subspecies of the 54 taxa (31 species, plus 22 additional named sub-species) currently recognized throughout the region, in addition to a subset of extra-Afrotropical taxa, by exploiting blood and archival samples. Employing a multi-locus phylogenetic approach and applying quantitative species delimitation we tested: 1) if there has been a single colonisation event of the Afrotropical realm; 2) if constituent mainland and island birds are monophyletic; and 3) if mainland diversity has been underestimated. Our comprehensive regional phylogeny revealed a single recent colonisation of the Afrotropical realm c.1.30 Ma from Asia, but a subsequent complex colonisation history between constituent island and mainland lineages during their radiation across this vast area. Our findings suggest a significant previous underestimation of continental species diversity and, based on this, we propose a revised taxonomy. Our study highlights the need to densely sample species diversity across ranges, providing key findings for future conservation assessments and establishing a robust framework for evolutionary studies

Analysis of virulence genes in Escherichia coli isolated from grated cheese

This research aimed to verify the presence of virulence genes in strains of Escherichia coli isolated from grated cheese sold in farmers' markets of Cuiaba-MT, Brazil. Forty samples of this food were submitted for microbiological analysis and 22 (55%) tested positive for E. coli. Next, 64 strains of E. coli were isolated from the positive samples and screened by the polymerase chain reaction (PCR) for the presence of the genes encoding the following virulence factors: stx1 and stx2 (verotoxin types 1 and 2), eae (intimin), lt1 (heat-labile toxin type 1), st1 (heat-stable toxin type 1), cnf1 and cnf2 (cytotoxic necrozing factor types 1 and 2), and cdtB (cytolethal distending toxin). All the isolates were negative for the genes stx1, stx2, eae, lt1, st1, cnf1, and cdtB, and five strains (7.81%) were positive for cnf2. A low prevalence of E. coli positive for virulence factors associated with the pathogenesis of diarrhoea was observed in this study. However, the presence of CNF-2 producing strains and the possibility of occurrence and scattering of other virulence factors that were not surveyed in the work indicate the risk related to the consumption of grated cheese from farmers' markets.31110610

Prevalence of enterotoxigenic and Shiga toxin-producing Escherichia coli in pigs slaughtered in Mato Grosso, Brazil

Introduction: This study aimed to estimate the prevalence of enterotoxigenic Escherichia coli (ETEC) and Shiga toxin-producing Escherichia coli (STEC) strains in pigs slaughtered in abattoirs located in the state of Mato Grosso, Brazil. Methodology: Intestinal samples from 74 animals were aseptically dissected and lumen content was plated on MacConkey agar. Confluent colonies from each plate were screened for the presence of ETEC and STEC strains by PCR assays. Results: It was verified that the prevalence of STEC and ETEC carriers was 1.35% and 9.46% respectively. One (1.35%) of the 74 samples tested was positive for the stx2 gene, and seven (9.46%) for st1, of which two (2.70%) were also positive for lt1. Conclusion: The results provided represent a benchmark for future research on pathogenic E. coli of porcine origin in Mato Grosso.5212312

Techniques for Arbuscular Mycorrhiza Inoculum Reduction

It is well established that arbuscular mycorrhizal (AM) fungi can play a significant role in sustainable crop production and environmental conservation. With the increasing awareness of the ecological significance of mycorrhizas and their diversity, research needs to be directed away from simple records of their occurrence or casual speculation of their function (Smith and Read 1997). Rather, the need is for empirical studies and investigations of the quantitative aspects of the distribution of different types and their contribution to the function of ecosystems. There is no such thing as a fungal effect or a plant effect, but there is an interaction between both symbionts. This results from the AM fungi and plant community size and structure, soil and climatic conditions, and the interplay between all these factors (Kahiluoto et al. 2000). Consequently, it is readily understood that it is the problems associated with methodology that limit our understanding of the functioning and effects of AM fungi within field communities. Given the ubiquous presence of AM fungi, a major constraint to the evaluation of the activity of AM colonisation has been the need to account for the indigenous soil native inoculum. This has to be controlled (i.e. reduced or eliminated) if we are to obtain a true control treatment for analysis of arbuscular mycorrhizas in natural substrates. There are various procedures possible for achieving such an objective, and the purpose of this chapter is to provide details of a number of techniques and present some evaluation of their advantages and disadvantages. Although there have been a large number of experiments to investigated the effectiveness of different sterilization procedures for reducing pathogenic soil fungi, little information is available on their impact on beneficial organisms such as AM fungi. Furthermore, some of the techniques have been shown to affect physical and chemical soil characteristics as well as eliminate soil microorganisms that can interfere with the development of mycorrhizas, and this creates difficulties in the interpretation of results simply in terms of possible mycorrhizal activity. An important subject is the differentiation of methods that involve sterilization from those focussed on indigenous inoculum reduction. Soil sterilization aims to destroy or eliminate microbial cells while maintaining the existing chemical and physical characteristics of the soil (Wolf and Skipper 1994). Consequently, it is often used for experiments focussed on specific AM fungi, or to establish a negative control in some other types of study. In contrast, the purpose of inoculum reduction techniques is to create a perturbation that will interfere with mycorrhizal formation, although not necessarily eliminating any component group within the inoculum. Such an approach allows the establishment of different degrees of mycorrhizal formation between treatments and the study of relative effects. Frequently the basic techniques used to achieve complete sterilization or just an inoculum reduction may be similar but the desired outcome is accomplished by adjustments of the dosage or intensity of the treatment. The ultimate choice of methodology for establishing an adequate non-mycorrhizal control depends on the design of the particular experiments, the facilities available and the amount of soil requiring treatment

Imaging Coulomb Islands in a Quantum Hall Interferometer

In the Quantum Hall regime, near integer filling factors, electrons should only be transmitted through spatially-separated edge states. However, in mesoscopic systems, electronic transmission turns out to be more complex, giving rise to a large spectrum of magnetoresistance oscillations. To explain these observations, recent models put forward that, as edge states come close to each other, electrons can hop between counterpropagating edge channels, or tunnel through Coulomb islands. Here, we use scanning gate microscopy to demonstrate the presence of quantum Hall Coulomb islands, and reveal the spatial structure of transport inside a quantum Hall interferometer. Electron islands locations are found by modulating the tunneling between edge states and confined electron orbits. Tuning the magnetic field, we unveil a continuous evolution of active electron islands. This allows to decrypt the complexity of high magnetic field magnetoresistance oscillations, and opens the way to further local scale manipulations of quantum Hall localized states

Comparing the effectiveness of the 0.018-inch versus the 0.022-inch bracket slot system in orthodontic treatment:study protocol for a randomized controlled trial

BACKGROUND: Edgewise fixed orthodontic appliances are available in two different bracket slot sizes (0.018 and 0.022 inch). Both systems are used by clinicians worldwide with some orthodontists claiming the superiority and clinical advantages of one system over the other. However, the scientific evidence supporting this area is scarce and weak. This leaves the clinician’s choice of bracket slot system to clinical preference. We aim to compare the 0.018-inch and 0.022-inch pre-adjusted bracket slot systems in terms of the effectiveness of orthodontic treatment. METHODS/DESIGN: This is a prospective, multicenter, randomized clinical trial, undertaken in the secondary care hospital environment in the NHS Tayside region of Scotland (United Kingdom). A total of 216 orthodontic patients will be recruited in three centers in secondary care hospitals in NHS Tayside. The participants will be randomly allocated to treatment with either the 0.018-inch or 0.022-inch bracket slot systems (n = 108 for each group) using Victory series™ conventional pre-adjusted bracket systems (3 M Unitek, Monrovia, United States). Baseline records and outcome data collected during and at the end of orthodontic treatment will be assessed. The primary outcome measures will be the duration of orthodontic treatment in the maxillary and mandibular arches. The secondary outcome measures will be the number of scheduled appointments for orthodontic treatment in the maxillary and mandibular arches, treatment outcome using Peer Assessment Rating index (PAR), orthodontically induced inflammatory root resorption (as measured using periapical radiographs) and the patient’s perception of wearing orthodontic appliances. DISCUSSION: The results from the current study will serve as evidence to guide the clinician in deciding whether the difference in bracket slot size has a significant impact on the effectiveness of orthodontic treatment. TRIAL REGISTRATION: Registered with ClinicalTrials.gov on 5 March 2014, registration number: NCT02080338