Comparisons of host susceptibility to isogenic virulent and hypovirulent [CHV1-infected] strains of Cryphonectria parasitica among Castanea hosts and plant tissue types

Chestnut blight is a devastating canker disease of numerous Castanea spp. resulting from the infection of wounds by Cryphonectria parasitica. The restoration of American chestnut has been pursued through the generation of blight resistant American x Chinese hybrids and employment of virulence attenuating hypoviruses of C. parasitica. The goals of this study were: 1) to conduct comparisons of host resistance among American (C. dentata), European (C. sativa), Chinese (C. mollisima), and three American x Chinese hybrid generations (B2F2, B2F3, B3F2) produced by The American Chestnut Foundation (TACF) to isogenic virulent and hypovirulent (CHV1) strains of C. parasitica; 2) to validate the high-throughput use and reproducibility of the chestnut leaf susceptibility assay against the same fungal strains on representative leaves sampled across the various host backgrounds; and 3) to conduct comparisons among hypovirulent strains of C. parasitica using living stem inoculation, excised-leaf, and apple assays. The comparison of host resistance was conducted on populations of trees growing at the West Virginia University agronomy farm. Infections were initiated on live-stems with a virulent strain designated \u27Weekly\u27 and an isogenic, hypovirulent \u27Weekly-CHV1\u27 strain (Euro7-CHV1). Subsequent canker measurements and fungal stromata counts were performed every two months for a year to assess host resistance. For virulent Weekly inoculations, Chinese chestnuts were often significantly more resistant, but few significant differences existed among the other hosts. Average linear growth measurements taken one year post-inoculation revealed B3F2 chestnuts to have the most linear growth of 20.02 cm and Chinese chestnuts to have the least linear growth of 13.92 cm. Stromata density estimates were highly variable within each host background with the highest density on B3F2 at an average of 0.65 stromata/cm 2 and the least on Chinese chestnuts at an average of 0.25 stromata/cm 2. Additional measurements taken for virulent Weekly inoculations hinted at a higher level of resistance within the B2F2 hybrid generation while all other hosts aside from Chinese were often similar to American chestnut. Weekly-CHV1 cankers expanded during the first two months of the study, but no subsequent growth was observed on any host despite the recovery of these isolates nine months post-inoculation. An excised-leaf assay was conducted using leaves from a subset of trees included in the living stem assay. Weekly and Weekly-CHV1 were used to inoculate the midvein of leaves from all previously mentioned host backgrounds. There were no significant differences for the Weekly isolate inoculations, but the average lesion area for American chestnut (78.5 mm2) was largest and Chinese chestnut (33.1 mm 2) was smallest among the tree species and breeding lines tested. For Weekly-CHV1 inoculations, Chinese chestnut (42.7 mm2) had significantly smaller lesion areas while all other hosts had average lesion areas similar to each other with the exception of B2F2 (63.72 mm2). Weekly (58.1 mm2) produced a significantly smaller average leaf-lesion area across all hosts than Weekly-CHV1 (86.4 mm 2). Further, the incidence of infection was significantly lower for Weekly (39.5%) than Weekly-CHV1 (79.1%). The virulence of selected hypovirulent isolates also was examined through a living branch assay that employed a clonal clump of wild American chestnut sprouts, an excised-leaf assay using leaves from the same clonal clump, and an apple assay. Weekly-CHV1 once again produced significantly smaller cankers in the living branch assay than Weekly. Interestingly, Weekly-CHV1 produced larger lesions than Weekly in the leaf and apple assays while all other virulent strains produced larger lesions than their hypovirulent counterparts. Host resistance and pathogen virulence are the balancing point for the survival of an infected chestnut host. Here, a selection of American, European, TACF hybrid chestnuts were shown to be equally susceptible to stem infections of C. parasitica. The excised-leaf assay produced similar results with regards to host response, but hypovirulent Weekly-CHV1 unexpectedly produced larger lesions than virulent Weekly. This same observation was made for an apple assay and a second excised-leaf assay. These findings provide evidence for unique interactions between C. parasitica and hypoviruses not previously observed

Assessment of minimally invasive direct coronary artery bypass grafting of the left internal thoracic artery by means of magnetic resonance imaging

ObjectivesWe sought to evaluate graft patency, flow, and flow reserve in patients with minimally invasive direct coronary artery bypass surgery of internal thoracic artery grafts by a combined magnetic resonance protocol with a phase-contrast technique and magnetic resonance angiography.MethodsAt 1.5 T (Magnetom Sonata, Siemens), 30 symptomatic patients with 30 left internal thoracic artery grafts were examined 6 years after minimally invasive surgical intervention. Navigator-gated magnetic resonance angiography and contrast-enhanced FLASH-3D magnetic resonance angiography (0.2 mmol gadopentate–diethylene triamine pentetic acid [Gd-DTPA]/kg body weight) was used to assess bypass patency. Phase-contrast flow measurements with retrospective gating were performed in the internal thoracic artery grafts at rest and after stress induction with dipyridamole (0.57 mg/kg body weight). Graft patency was evaluated by means of multidetector computed tomography (Sensation 16, Siemens).ResultsInternal thoracic artery grafts were occluded in 5 of 30 patients. In 6 patients the anastomosis to the left anterior descending artery was highly stenotic (>70%) at multidetector computed tomography. In patients with regular grafts (multidetector computed tomography), a significant improvement of graft flow (P < .001) and diastolic/systolic peak velocity ratio (P < .001) after stress induction was detected. Magnetic resonance angiography combined with flow reserve measurements could differentiate between occluded-stenotic and regular minimally invasive direct coronary artery bypass grafts.ConclusionsMagnetic resonance imaging allows a combined assessment of bypass patency and flow with flow reserve in patients after the minimally invasive direct coronary artery bypass operation. The protocol of this study might be applicable for the evaluation of graft status in symptomatic patients after revascularization

Functional connectome of arousal and motor brainstem nuclei in living humans by 7 Tesla resting-state fMRI

Brainstem nuclei play a pivotal role in many functions, such as arousal and motor control. Nevertheless, the connectivity of arousal and motor brainstem nuclei is understudied in living humans due to the limited sensitivity and spatial resolution of conventional imaging, and to the lack of atlases of these deep tiny regions of the brain. For a holistic comprehension of sleep, arousal and associated motor processes, we investigated in 20 healthy subjects the resting-state functional connectivity of 18 arousal and motor brainstem nuclei in living humans. To do so, we used high spatial-resolution 7 Tesla resting-state fMRI, as well as a recently developed in-vivo probabilistic atlas of these nuclei in stereotactic space. Further, we verified the translatability of our brainstem connectome approach to conventional (e.g. 3 Tesla) fMRI. Arousal brainstem nuclei displayed high interconnectivity, as well as connectivity to the thalamus, hypothalamus, basal forebrain and frontal cortex, in line with animal studies and as expected for arousal regions. Motor brainstem nuclei showed expected connectivity to the cerebellum, basal ganglia and motor cortex, as well as high interconnectivity. Comparison of 3 Tesla to 7 Tesla connectivity results indicated good translatability of our brainstem connectome approach to conventional fMRI, especially for cortical and subcortical (non-brainstem) targets and to a lesser extent for brainstem targets. The functional connectome of 18 arousal and motor brainstem nuclei with the rest of the brain might provide a better understanding of arousal, sleep and accompanying motor functions in living humans in health and disease

Konzeption und Entwicklung eines Condition Monitoring Systems mit Low Cost Sensoren zur Überwachung von Roboterschwingungen

Im Rahmen dieser Veröffentlichung wird ein Konzept zur Erfassung des Schwingungsverhaltens von Industrierobotern mit Hilfe von Low Cost Sensoren vorgestellt. Durch dieses sollen die dynamischen Eigenschaften des Industrieroboters im gesamten Arbeitsraum untersucht werden. Die Roboterstruktur wird dazu durch eine speziell konstruierte Unwuchtscheibe angeregt. Das Messsystem besteht aus einem Beschleunigungssensor, einem Arduino-Mikrocontroller und einem eigens entwickelten Mess- und Auswerteprogramm in der Softwareumgebung MATLAB®. Die Validierung des Konzeptes erfolgt jeweils mit Messreihen an einem Kragbalken sowie an einem Industrieroboter durch den Vergleich mit einem Referenzmesssystem der Firma Brüel & Kjaer. Durch das entwickelte Low Cost Condition Monitoring System lassen sich die Anregungsfrequenzen und –amplituden mit hinreichender Genauigkeit erfassen und Rückschlüsse auf das Schwingungsverhalten des Industrieroboters ziehen

Functional connectome of brainstem nuclei involved in autonomic, limbic, pain and sensory processing in living humans from 7 Tesla resting state fMRI

Despite remarkable advances in mapping the functional connectivity of the cortex, the functional connectivity of subcortical regions is understudied in living humans. This is the case for brainstem nuclei that control vital processes, such as autonomic, limbic, nociceptive and sensory functions. This is because of the lack of precise brainstem nuclei localization, of adequate sensitivity and resolution in the deepest brain regions, as well as of optimized processing for the brainstem. To close the gap between the cortex and the brainstem, on 20 healthy subjects, we computed a correlation-based functional connectome of 15 brainstem nuclei involved in autonomic, limbic, nociceptive, and sensory function (superior and inferior colliculi, ventral tegmental area-parabrachial pigmented nucleus complex, microcellular tegmental nucleus-prabigeminal nucleus complex, lateral and medial parabrachial nuclei, vestibular and superior olivary complex, superior and inferior medullary reticular formation, viscerosensory motor nucleus, raphe magnus, pallidus, and obscurus, and parvicellular reticular nucleus – alpha part) with the rest of the brain. Specifically, we exploited 1.1mm isotropic resolution 7 Tesla resting-state fMRI, ad-hoc coregistration and physiological noise correction strategies, and a recently developed probabilistic template of brainstem nuclei. Further, we used 2.5mm isotropic resolution resting-state fMRI data acquired on a 3 Tesla scanner to assess the translatability of our results to conventional datasets. We report highly consistent correlation coefficients across subjects, confirming available literature on autonomic, limbic, nociceptive and sensory pathways, as well as high interconnectivity within the central autonomic network and the vestibular network. Interestingly, our results showed evidence of vestibulo-autonomic interactions in line with previous work. Comparison of 7 Tesla and 3 Tesla findings showed high translatability of results to conventional settings for brainstem-cortical connectivity and good yet weaker translatability for brainstem-brainstem connectivity. The brainstem functional connectome might bring new insight in the understanding of autonomic, limbic, nociceptive and sensory function in health and disease

gbpA as a Novel qPCR Target for the Species-Specific Detection of Vibrio cholerae O1, O139, Non-O1/Non-O139 in Environmental, Stool, and Historical Continuous Plankton Recorder Samples

The Vibrio cholerae N-acetyl glucosamine-binding protein A (GbpA) is a chitin-binding protein involved in V . cholerae attachment to environmental chitin surfaces and human intestinal cells. We previously investigated the distribution and genetic variations of gbpA in a large collection of V . cholerae strains and found that the gene is consistently present and highly conserved in this species. Primers and probe were designed from the gbpA sequence of V . cholerae and a new Taq-based qPCR protocol was developed for diagnostic detection and quantification of the bacterium in environmental and stool samples. In addition, the positions of primers targeting the gbpA gene region were selected to obtain a short amplified fragment of 206 bp and the protocol was optimized for the analysis of formalin-fixed samples, such as historical Continuous Plankton Recorder (CPR) samples. Overall, the method is sensitive (50 gene copies), highly specific for V . cholerae and failed to amplify strains of the closely-related species Vibrio mimicus . The sensitivity of the assay applied to environmental and stool samples spiked with V . cholerae ATCC 39315 was comparable to that of pure cultures and was of 10 2 genomic units/l for drinking and seawater samples, 10 1 genomic units/g for sediment and 10 2 genomic units/g for bivalve and stool samples. The method also performs well when tested on artificially formalin-fixed and degraded genomic samples and was able to amplify V . cholerae DNA in historical CPR samples, the earliest of which date back to August 1966. The detection of V . cholerae in CPR samples collected in cholera endemic areas such as the Benguela Current Large Marine Ecosystem (BCLME) is of particular significance and represents a proof of concept for the possible use of the CPR technology and the developed qPCR assay in cholera studies