290 research outputs found
Tetraamine Me6TREN induced monomerization of alkali metal borohydrides and aluminohydrides
Monomeric 1:1 complexes of MEH4 (M, E = Li, B, 1; Na, B, 2; Li, Al, 3; Na, Al, 4) and the tripodal tetradentate ligand (Me2NCH2CH2)3N (Me6TREN) have been prepared in good yields by refluxing in THF and allowing the solutions to cool slowly. X-ray diffraction studies show that the BH4 group binds to either Li or Na via three hydride bridges while the AlH4 group connects to Li via a single hydride bridge. Surprisingly, Me6TREN·LiAlH4 represents the first monomeric contacted ion pair LiAlH4 derivative to be structurally characterized. In every case the tetraamine coordinates via all four of its Lewis basic nitrogen atoms. A similar protocol using the alkyl-rich borohydride MBEt3H also gives monomeric species (M = Li, 5; Na, 6). All complexes have been characterized in solution by multinuclear (1H, 7Li, 11B, 13C and 27Al, where appropriate) NMR spectroscopy which reveals excellent textbook examples of 1J coupling between B/Al and H in the cases of complexes 1-4 and between B and C in the cases of complexes 5 and 6
PERSONALIZED MEDICINE: The Challenge for the Health Care System and the Community
Objectives To determine those performance indicators that have the greatest influence on classifying outcome at the elite level of mixed martial arts (MMA). A secondary objective was to establish the efficacy of decision tree analysis in explaining the characteristics of victory when compared to alternate statistical methods. Design Cross-sectional observational. Methods Eleven raw performance indicators from male Ultimate Fighting Championship bouts (n = 234) from July 2014 to December 2014 were screened for analysis. Each raw performance indicator was also converted to a rate-dependent measure to be scaled to fight duration. Further, three additional performance indicators were calculated from the dataset and included in the analysis. Cohen\u27s d effect sizes were employed to determine the magnitude of the differences between Wins and Losses, while decision tree (chi-square automatic interaction detector (CHAID)) and discriminant function analyses (DFA) were used to classify outcome (Win and Loss). Results Effect size comparisons revealed differences between Wins and Losses across a number of performance indicators. Decision tree (raw: 71.8%; rate-scaled: 76.3%) and DFA (raw: 71.4%; rate-scaled 71.2%) achieved similar classification accuracies. Grappling and accuracy performance indicators were the most influential in explaining outcome. The decision tree models also revealed multiple combinations of performance indicators leading to victory. Conclusions The decision tree analyses suggest that grappling activity and technique accuracy are of particular importance in achieving victory in elite-level MMA competition. The DFA results supported the importance of these performance indicators. Decision tree induction represents an intuitive and slightly more accurate approach to explaining bout outcome in this sport when compared to DFA
The Epidemiology, Management, and Outcome of Field Hockey-related Fractures in a Standard Population
Background: Field hockey is one of the most popular sports in the world, yet little is known about patient outcome following fracture injuries sustained during this sport. Objectives: The aim of this study is to describe the epidemiology, management, and outcome of field hockey-related fractures in a known UK population at all skill levels. Materials and Methods: All fractures sustained during field hockey from 2007 to 2008 within the adult Lothian population were prospectively recorded and confirmed by an orthopedic surgeon during treatment at the sole adult orthopedic center in the region. Nonresident individuals were not included in the study. Follow-up data were obtained in September 2010 to determine return rates and times to field hockey. Results: Nineteen fractures were recorded over the study period in 19 patients. Seventeen (89) of the fractures were recorded in the upper limb, with 15 (79) recorded in hand. Eighteen fractures (85) in 18 patients (95) were followed up at a mean interval of 31 months (range: 25-37 months; standard deviation SD 2.1 months). The mean time for return to field hockey from injury was 10.8 weeks (range: 3-26 weeks; SD 7.1 weeks). For patients with upper limb injuries, the mean time was 9.2 weeks (range: 3-20 weeks; SD 5.7 weeks), compared to 22 weeks (range: 18-26 weeks; SD 5.7 weeks) for patients with lower limb injuries. Eleven percent of the cohort did not return to field hockey. Seventy-eight percent of the cohort returned to field hockey at the same level or higher. Fifty percent had ongoing related problems, yet only 17% had impaired field hockey ability because of these problems. Fractures with the highest morbidity in not returning to field hockey were as follows: Metacarpal 14% and finger phalanx 13%. Conclusions: The significant majority of field hockey-related fractures are sustained in the upper limb, notably the hand. Around ninety percent of patients sustaining a fracture during field hockey will return to this sport at a similar level. While half of these will have persisting symptoms 2 years postinjury, only one-third of symptomatic patients will have impaired field hockey ability because of this
Magnetism and transport in transparent high-mobility BaSnO3 films doped with La, Pr, Nd, and Gd
We have explored the effect of magnetic rare-earth dopants substitutionally incorporated on the Ba sites of BaSnO3 in terms of electronic transport, magnetism, and optical properties. We show that for Ba0.92R0.08SnO3 thin films (where R=La,Pr,Nd,Gd), there is a linear increase of mobility with carrier concentration across all doping schemes. La-doped films have the highest mobilities, followed by Pr- and Nd-doped films. Gd-doped samples have the largest ionic size mismatch with the Ba site and correspondingly the lowest carrier concentrations and electron mobilities. However, crystallinity does not appear to be a strong predictor of transport phenomena; our results suggest that point defects more than grain boundaries are key ingredients in tuning the conduction of BaSnO3 films grown by pulsed laser deposition. Pronounced, nonhysteretic x-ray magnetic dichroism signals are observed for Pr-, Nd-, and Gd-doped samples, indicating paramagnetism. Finally, we probe the optical constants for each of the BaSnO3 doping schemes and note that there is little change in the transmittance across all samples. Together these results shed light on conduction mechanisms in BaSnO3 doped with rare-earth cations
Seismic imaging in Long Valley, California, by surface and borehole techniques: An investigation of active tectonics
The search for silicic magma in the upper crust is converging on the Long Valley Caldera of eastern California, where several lines of geophysical evidence show that an active magma chamber exists at midâto lowerâcrustal depths. There are also other strong indications that magma may be present at depths no greater than about 5 km below the surface. In this paper, we review the history of the search for magma at Long Valley. We also present the preliminary results from a coordinated suite of seismic experiments, conducted by a consortium of institutions in the summer and fall of 1984, that were designed to refine our knowledge of the upper extent of the magma chamber. Major funding for the experiments was provided by the Geothermal Research Program of the U.S. Geological Survey (USGS) and by the Magma Energy Technology Program of the U.S. Department of Energy (DOE), a program to develop the technology necessary to extract energy directly from crustal magma. Additional funding came from DOE's Office of Basic Energy Sciences and the National Science Foundation (NSF). Also, because extensive use was made of a 0.9âkmâdeep well lent to us by Santa Fe Geothermal, Inc., the project was conducted partly under the auspices of the Continental Scientific Drilling Program (CSDP). As an integrated seismic study of the crust within the caldera that involved the close cooperation of a large number of institutions, the project was moreover viewed as a prototype for future scientific experiments to be conducted under the Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL). The experiment thus represented a unique blend of CSDP and PASSCAL methods, and achieved goals consistent with both programs
Detection of SARSâCoVâ2 in respiratory samples from cats in the UK associated with humanâtoâcat transmission
Objectives: The aim of the study was to find evidence of SARSâCoVâ2 infection in UK cats. Design: Tissue samples were tested for SARSâCoVâ2 antigen using immunofluorescence and for viral RNA by in situ hybridisation. A set of 387 oropharyngeal swabs that had been submitted for routine respiratory pathogen testing was tested for SARSâCoVâ2 RNA using reverse transcriptase quantitative PCR. Results: Lung tissue collected postâmortem from cat 1 tested positive for both SARSâCoVâ2 nucleocapsid antigen and RNA. SARSâCoVâ2 RNA was detected in an oropharyngeal swab collected from cat 2 that presented with rhinitis and conjunctivitis. High throughput sequencing of the viral genome revealed five single nucleotide polymorphisms (SNPs) compared to the nearest UK human SARSâCoVâ2 sequence, and this human virus contained eight SNPs compared to the original WuhanâHuâ1 reference sequence. An analysis of the viral genome of cat 2 together with nine other felineâderived SARSâCoVâ2 sequences from around the world revealed no shared catâspecific mutations. Conclusions: These findings indicate that humanâtoâcat transmission of SARSâCoVâ2 occurred during the COVIDâ19 pandemic in the UK, with the infected cats developing mild or severe respiratory disease. Given the ability of the new coronavirus to infect different species, it will be important to monitor for humanâtoâcat, catâtoâcat and catâtoâhuman transmission
Generation and transmission of interlineage recombinants in the SARS-CoV-2 pandemic.
We present evidence for multiple independent origins of recombinant SARS-CoV-2 viruses sampled from late 2020 and early 2021 in the United Kingdom. Their genomes carry single-nucleotide polymorphisms and deletions that are characteristic of the B.1.1.7 variant of concern but lack the full complement of lineage-defining mutations. Instead, the remainder of their genomes share contiguous genetic variation with non-B.1.1.7 viruses circulating in the same geographic area at the same time as the recombinants. In four instances, there was evidence for onward transmission of a recombinant-origin virus, including one transmission cluster of 45 sequenced cases over the course of 2Â months. The inferred genomic locations of recombination breakpoints suggest that every community-transmitted recombinant virus inherited its spike region from a B.1.1.7 parental virus, consistent with a transmission advantage for B.1.1.7's set of mutations.The COG-UK Consortium is supported by funding from the Medical Research Council (MRC) part of UK Research & Innovation (UKRI), the National Institute of Health Research (NIHR) (MC_PC_19027), and Genome Research Limited, operating as the Wellcome Sanger Institute. O.G.P. was supported by the Oxford Martin School. J.T.M., R.M.C., N.J.L., and A.R. acknowledge the support of the Wellcome Trust (Collaborators Award 206298/Z/17/Z â ARTIC network). D.L.R. acknowledges the support of the MRC (MC_UU_12014/12) and the Wellcome Trust (220977/Z/20/Z). E.S. and A.R. are supported by the European Research Council (grant agreement no. 725422 â ReservoirDOCS). T.R.C. and N.J.L. acknowledge the support of the MRC, which provided the funding for the MRC CLIMB infrastructure used to analyze, store, and share the UK sequencing dataset (MR/L015080/1 and MR/T030062/1). The samples sequenced in Wales were sequenced partly using funding provided by the Welsh Government
Analysis of high-depth sequence data for studying viral diversity: a comparison of next generation sequencing platforms using Segminator II
Background:
Next generation sequencing provides detailed insight into the variation present within viral populations, introducing the possibility of treatment strategies that are both reactive and predictive. Current software tools, however, need to be scaled up to accommodate for high-depth viral data sets, which are often temporally or spatially linked. In addition, due to the development of novel sequencing platforms and chemistries, each with implicit strengths and weaknesses, it will be helpful for researchers to be able to routinely compare and combine data sets from different platforms/chemistries. In particular, error associated with a specific sequencing process must be quantified so that true biological variation may be identified.
Results:
Segminator II was developed to allow for the efficient comparison of data sets derived from different sources. We demonstrate its usage by comparing large data sets from 12 influenza H1N1 samples sequenced on both the 454 Life Sciences and Illumina platforms, permitting quantification of platform error. For mismatches median error rates at 0.10 and 0.12%, respectively, suggested that both platforms performed similarly. For insertions and deletions median error rates within the 454 data (at 0.3 and 0.2%, respectively) were significantly higher than those within the Illumina data (0.004 and 0.006%, respectively). In agreement with previous observations these higher rates were strongly associated with homopolymeric stretches on the 454 platform. Outside of such regions both platforms had similar indel error profiles. Additionally, we apply our software to the identification of low frequency variants.
Conclusion:
We have demonstrated, using Segminator II, that it is possible to distinguish platform specific error from biological variation using data derived from two different platforms. We have used this approach to quantify the amount of error present within the 454 and Illumina platforms in relation to genomic location as well as location on the read. Given that next generation data is increasingly important in the analysis of drug-resistance and vaccine trials, this software will be useful to the pathogen research community. A zip file containing the source code and jar file is freely available for download from http://www.bioinf.manchester.ac.uk/segminator/
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