An alien ectosymbiotic branchiobdellidan (Annelida: Clitellata) adopting exotic crayfish: a biological co-invasion with unpredictable consequences

Invasive alien species present a global threat to biodiversity, particularly where pathogens and symbionts are involved. Branchiobdellidans are clitellate annelids with an obligate ectosymbiotic association primarily on astacoidean crayfish. There are several examples of branchiobdellidan species adopting a geographically exotic host where endemic and exotic crayfishes cohabit the same water body. The first records of a western North American branchiobdellidan, Xironogiton victoriensis, adopting the eastern North American crayfish, Procambarus clarkii, in 2 river basins in Spain provide further evidence of the ectosymbionts’ tolerance to adopt an exotic host. Given worldwide translocations of these and other commercial crayfish species, limnologists and agency managers need to be alert for further introductions of X. victoriensis and other branchiobdellidans. Impacts of these exotic ectosymbionts on habitat and biota at a new location are unknown, as are their consequences on native biodiversity

Estimated incidence of previously undetected atrial fibrillation on a 14-day continuous electrocardiographic monitor and associated risk of stroke

Aims There is uncertainty about whether and how to perform screening for atrial fibrillation (AF). To estimate the incidence of previously undetected AF that would be captured using a continuous 14-day ECG monitor and the associated risk of stroke. Methods and results We analysed data from a cohort of patients >65 years old with hypertension and a pacemaker, but without known AF. For each participant, we simulated 1000 ECG monitors by randomly selecting 14-day windows in the 6 months following enrolment and calculated the average AF burden (total time in AF). We used Cox proportional hazards models adjusted for CHA(2)DS(2)-VASc score to estimate the risk of subsequent ischaemic stroke or systemic embolism (SSE) associated with burdens of AF > and 6 min was 3.10% (95% CI 2.53-3.72). This was consistent across strata of age and CHA(2)DS(2)-VASc scores. Over a mean follow-up of 2.4 years, the rate of SSE among patients with 6 min of AF. Conclusions Approximately 3% of individuals aged >65 years with hypertension may have more than 6 min of AF detected by a 14-day ECG monitor. This is associated with a stroke risk of over 2% per year. Whether oral anticoagulation will reduce stroke in these patients is unknown

An alien ectosymbiotic branchiobdellidan (Annelida: Clitellata) adopting exotic crayfish: a biological co-invasion with unpredictable consequences

Invasive alien species present a global threat to biodiversity, particularly where pathogens and symbionts are involved. Branchiobdellidans are clitellate annelids with an obligate ectosymbiotic association primarily on astacoidean crayfish. There are several examples of branchiobdellidan species adopting a geographically exotic host where endemic and exotic crayfishes cohabit the same water body. The first records of a western North American branchiobdellidan, Xironogiton victoriensis, adopting the eastern North American crayfish, Procambarus clarkii, in 2 river basins in Spain provide further evidence of the ectosymbionts’ tolerance to adopt an exotic host. Given worldwide translocations of these and other commercial crayfish species, limnologists and agency managers need to be alert for further introductions of X. victoriensis and other branchiobdellidans. Impacts of these exotic ectosymbionts on habitat and biota at a new location are unknown, as are their consequences on native biodiversit

Magnetic resonance enterography, small bowel ultrasound and colonoscopy to diagnose and stage Crohn’s disease; patient acceptability, and perceived burden

Objectives: To compare patient acceptability and burden of magnetic resonance enterography (MRE) and ultrasound (US) to each other, and to other enteric investigations, particularly colonoscopy. Methods: 159 patients (mean age 38, 94 female) with newly diagnosed or relapsing Crohn’s disease, prospectively recruited to a multicentre diagnostic accuracy study comparing MRE and US, completed an experience questionnaire on the burden and acceptability of small bowel investigations between December 2013 and September 2016. Acceptability, recovery time, scan burden and willingness to repeat the test were analysed using the Wilcoxon signed rank and McNemar tests; and group differences in scan burden with Mann-Whitney U and Kruskal-Wallis tests. Results: Overall, 128 (88%) patients rated MRE as very or fairly acceptable, lower than US (144, 99%; p<0.001), but greater than colonoscopy (60, 60%; p<0.001). MRE recovery time was longer than US (p<0.001), but shorter than colonoscopy (p<0.001). Patients were less willing to undergo MRE again than US (127 vs 133, 91% vs. 99%; p=0.012), but more willing than for colonoscopy (68, 75%; p=0.017). MRE generated greater burden than US (p<0.001), although burden scores were low. Younger age and emotional distress were associated with greater MRE and US burden. Higher MRE discomfort was associated with patient preference for US (p=0.053). Patients rated test accuracy as more important than scan discomfort. Conclusions.: MRE and US are well tolerated. Although MRE generates greater burden, longer recovery, and is less preferred than US, it is more acceptable than colonoscopy. Patients however place greater emphasis on diagnostic accuracy than burden

Multi-ethnic genome-wide association study for atrial fibrillation

Atrial fibrillation (AF) affects more than 33 million individuals worldwide and has a complex heritability. We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF

The effect of talker and intonation variability on speech perception in noise in children with dyslexia.

In this study, the authors aimed to determine whether children with dyslexia (hereafter referred to as "DYS children") are more affected than children with average reading ability (hereafter referred to as "AR children") by talker and intonation variability when perceiving speech in noise

First report of two North American branchiobdellidans (Annelida: Clitellata) or crayfish worms on signal crayfish in Europe with a discussion of similar introductions into Japan

Two species of North American branchiobdellidans, Cambarincola gracilis Robinson, 1954 and Cambarincola okadai Yamaguchi, 1933, have been reported in Europe for the first time. These branchiobdellidans together with Xirogoniton victoriensis Gelder and Hall, 1990 were found on signal crayfish, Pacifastacus leniusculus (Dana, 1852), collected from the Lot and Tarn River drainages in southern France. Specimens of X. victoriensis were also reported on the same host in the Mayenne River drainage in northeastern France. Brief morphological descriptions of the three alien branchiobdellidan species are given. These introductions are briefly discussed and compared with similar alien ectosymbiotic associations found in Japan

A new kid in town: First case of an alien worm, Xironogiton victoriensis (Annelida: Clitellata) on a native European freshwater crayfish

Worldwide biodiversity is suffering a “biogeographical homogenization” due to biological invasions. The translocation of freshwater crayfish around the world for aquaculture and the pet trade is also spreading their symbionts, so that all of the association's members have the potential to form invasive populations. In Europe, the signal crayfish, Pacifastacus leniusculus, is often concomitant with the branchiobdellidan Xironogiton victoriensis and through repeated translocations their ranges are expanding. In this study, we report the first observation of X. victoriensis on a native European crayfish population of Austropotamobius pallipes. This work is an alert to the authorities and decision makers on the risks to native species when aquaculture projects introduce alien crayfish species and their symbionts into an area. Future studies are needed to evaluate the impact of this non-native ectosymbiont on native crayfish populations