379 research outputs found
Diversity And Ecology Of Bean Pod Mottle Virus In Mississippi
Sequences of 33 Bean pod mottle virus (BPMV) isolates collected from Mississippi were obtained from four regions of the viral genome. Sequences were compared mutually and to subgroups I and II type isolates. Mississippi isolates collected have greater similarity to subgroup II. Helicase sequences obtained from Mississippi isolates showed characteristics of isolates producing mild or moderate symptoms. Biological comparison of isolates from Mississippi confirmed predictions from molecular data. Plant species were tested for susceptibility to BPMV. Seven of 52 species tested positive. Desmodium perplexum was infected by beetle feeding and served as an inoculum source for transmission of BPMV to soybeans. Beetle species collected from soybean and clover were tested to determine if they serve as BPMV vectors. Of eight species tested, Hypera postica transmitted BPMV to 1 of 14 test plants. Beetle overwintering transmission of BPMV was tested, but of 187 beetles collected, none transmitted the virus
Diversity And Ecology Of Bean Pod Mottle Virus In Mississippi
Sequences of 33 Bean pod mottle virus (BPMV) isolates collected from Mississippi were obtained from four regions of the viral genome. Sequences were compared mutually and to subgroups I and II type isolates. Mississippi isolates collected have greater similarity to subgroup II. Helicase sequences obtained from Mississippi isolates showed characteristics of isolates producing mild or moderate symptoms. Biological comparison of isolates from Mississippi confirmed predictions from molecular data. Plant species were tested for susceptibility to BPMV. Seven of 52 species tested positive. Desmodium perplexum was infected by beetle feeding and served as an inoculum source for transmission of BPMV to soybeans. Beetle species collected from soybean and clover were tested to determine if they serve as BPMV vectors. Of eight species tested, Hypera postica transmitted BPMV to 1 of 14 test plants. Beetle overwintering transmission of BPMV was tested, but of 187 beetles collected, none transmitted the virus
Comparing the effectiveness of polymer debriding devices using a porcine wound biofilm model
Objective: Debridement to remove necrotic and/or infected tissue and promote active healing remains a cornerstone of contemporary chronic wound management. While there has been a recent shift toward less invasive polymer-based debriding devices, their efficacy requires rigorous evaluation.Approach: This study was designed to directly compare monofilament debriding devices to traditional gauze using a wounded porcine skin biofilm model with standardized application parameters. Biofilm removal was determined using a surface viability assay, bacterial counts, histological assessment, and scanning electron microscopy (SEM).Results: Quantitative analysis revealed that monofilament debriding devices outperformed the standard gauze, resulting in up to 100-fold greater reduction in bacterial counts. Interestingly, histological and morphological analyses suggested that debridement not only removed bacteria, but also differentially disrupted the bacterially-derived extracellular polymeric substance. Finally, SEM of post-debridement monofilaments showed structural changes in attached bacteria, implying a negative impact on viability.Innovation: This is the first study to combine controlled and defined debridement application with a biologically relevant ex vivo biofilm model to directly compare monofilament debriding devices.Conclusion: These data support the use of monofilament debriding devices for the removal of established wound biofilms and suggest variable efficacy towards biofilms composed of different species of bacteria
Late Cretaceous-Cenozoic basin inversion and palaeostress fields in the North Atlantic-western Alpine-Tethys realm : implications for intraplate tectonics
The authors wish to acknowledge the feedback of two anonymous reviewers, whose comments and suggestions have led to a substantially improved manuscript. CS's (now at Uppsala University, Sweden) postdoctoral fellowship at Durham University was financed by the Carlsberg Foundation. AP's (now at McMaster University, Canada) postdoctoral fellowship at Memorial University of Newfoundland was funded by the Hibernia project geophysics support fund. SJ's postdoctoral fellowship at the University of Calgary is funded by Natural Sciences and Engineering Research Council of Canada.Peer reviewedPostprin
Establishing the Response of Low Frequency Auditory Filters
The response of auditory filters is central to frequency selectivity of sound by the human auditory system. This is true especially for realistic complex sounds that are often encountered in many applications such as modeling the audibility of sound, voice recognition, noise cancelation, and the development of advanced hearing aid devices. The purpose of this study was to establish the response of low frequency (below 100Hz) auditory filters. Two experiments were designed and executed; the first was to measure subject's hearing threshold for pure tones (at 25, 31.5, 40, 50, 63 and 80 Hz), and the second was to measure the Psychophysical Tuning Curves (PTCs) at two signal frequencies (Fs= 40 and 63Hz). Experiment 1 involved 36 subjects while experiment 2 used 20 subjects selected from experiment 1. Both experiments were based on a 3-down 1-up 3AFC adaptive staircase test procedure using either a variable level narrow-band noise masker or a tone. A summary of the results includes masked threshold data in form of PTCs, the response of auditory filters, their distribution, and comparison with similar recently published data
First Observation of 15Be
The neutron-unbound nucleus 15Be was observed for the first time. It was populated using neutron transfer from a deuterated polyethylene target with a 59 MeV/u 14Be beam. Neutrons were measured in coincidence with outgoing 14Be particles and the reconstructed decay energy spectrum exhibits a resonance at 1.8(1) MeV. This corresponds to 15Be being unbound by 0.45 MeV more then 16Be thus significantly hindering the sequential two-neutron decay of 16Be to 14Be through this state
Characterization of Low Frequency Auditory Filters
The purpose of this study is to characterize auditory filters at low frequencies, defined as below about 100 Hz. Three experiments were designed and executed. They were conducted in the Exterior Effects Room at the NASA Langley Research Center, a psychoacoustic facility designed for presentation of aircraft flyover sounds to groups of test subjects. The first experiment measured 36 subjects hearing threshold for pure tones (at 25, 31.5, 40, 50, 63 and 80 Hz) in quiet conditions. The subjects, male and female, had a wide age range. This experiment allowed the performance of the test facility to be assessed and also provided screened test subjects for participation in subsequent experiments. The second and third experiments used 20 and 10 test subjects, respectively, and measured psychophysical tuning curves (PTCs) that describe auditory filters with center frequencies of approximately 63 and 50 Hz. The latter is assumed to be the lowest (bottom) auditory filter; thus, sounds at frequencies below about 50 Hz are perceived via the lower skirt of this lowest filter. All experiments used an adaptive, three-alternative forced-choice test procedure using either variable level tones or variable level, narrowband noise maskers. Measured PTCs were found to be very similar to other recently published data, both in terms of mean values and intersubject variation, despite different experimental protocols, different test facilities, and a wide range in subjects age
Further Insights into the Reaction Be14(CH2,X)10He
A previously published measurement of the reaction of a 59 MeV/nucleon 14Be beam on a deuterated polyethylene target was further analyzed to search for 12He as well as initial state effects in the population of the 10He ground state. No evidence for either was found. A lower limit of about 1 MeV was determined for a possible resonance in 12He. In addition, the three-body decay energy spectrum of 10He could not be described by a reaction mechanism calculation based on the halo structure of the initial 14Be assuming a direct α-particle removal reaction
Application of Palladium-Mediated 18F-Fluorination to PET Radiotracer Development: Overcoming Hurdles to Translation
New chemistry methods for the synthesis of radiolabeled small molecules have the potential to impact clinical positron emission tomography (PET) imaging, if they can be successfully translated. However, progression of modern reactions from the stage of synthetic chemistry development to the preparation of radiotracer doses ready for use in human PET imaging is challenging and rare. Here we describe the process of and the successful translation of a modern palladium-mediated fluorination reaction to non-human primate (NHP) baboon PET imaging–an important milestone on the path to human PET imaging. The method, which transforms [18F]fluoride into an electrophilic fluorination reagent, provides access to aryl–18F bonds that would be challenging to synthesize via conventional radiochemistry methods.Chemistry and Chemical Biolog
Structure and Decay Correlations of Two-Neutron Systems Beyond the Dripline
The two-neutron unbound systems of 16Be, 13Li, 10He, and 26O have been measured using the Modular Neutron Array (MoNA) and 4 Tm Sweeper magnet setup. The correlations of the 3-body decay for the 16Be and 13Li were extracted and demonstrated a strong correlated enhancement between the two neutrons. The measurement of the 10He ground state resonance from a 14Be(−2p2n) reaction provided insight into previous predictions that wavefunction of the entrance channel, projectile, can influence the observed decay energy spectrum for the unbound system. Lastly, the decay-in-target (DiT) technique was utilized to extract the lifetime of the 26O ground state. The measured lifetime of 4.5+1.1 −1.5 (stat.)±3(sys.) ps provides the first indication of two-neutron radioactivity
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