433 research outputs found
Structure of the chlorobenzene–argon dimer: Microwave spectrum and ab initio analysis
The rotational spectra of the 35Cl35Cl and 37Cl37Cl isotopes of the chlorobenzene–argon van der Waals dimer have been assigned using Fourier transform microwave spectroscopy techniques. Rotational constants and chlorine nuclear quadrupole coupling constants were determined which confirm that the complex has CsCs symmetry. The argon is over the aromatic ring, shifted from a position above the geometrical ring center towards the substituted carbon atom, and at a distance of about 3.68 Å from it. This distance is 0.1–0.2 Å shorter than the similar distance in the benzene–argon and fluorobenzene–argon complexes. Experimental results are confirmed and explained with the help of second-order Møller–Plesset perturbation calculations using a VDZP+diffVDZP+diff basis set. The complex binding energy of the chlorobenzene–argon complex is 1.28 kcal/mol (fluorobenzene–argon, 1.17; benzene–argon, 1.12 kcal/mol) reflecting an increase in stability caused by larger dispersion interactions when replacing one benzene H atom by F or by Cl. The structure and stability of Ar⋅C6H5–XAr⋅C6H5–X complexes are explained in terms of a balance between stabilizing dispersion and destabilizing exchange repulsion interactions between the monomers. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70251/2/JCPSA6-113-20-9051-1.pd
Widefield two-photon excitation without scanning : live cell microscopy with high time resolution and low photo-bleaching
We demonstrate fluorescence imaging by two-photon excitation without scanning in biological specimens as previously described by Hwang and co-workers, but with an increased field size and with framing rates of up to 100 Hz. During recordings of synaptically-driven Ca2+ events in primary rat hippocampal neurone cultures loaded with the fluorescent Ca2+ indicator Fluo-4 AM, we have observed greatly reduced photo-bleaching in comparison with single-photon excitation. This method, which requires no costly additions to the microscope, promises to be useful for work where high time-resolution is required
The Vehicle, Fall 1987
Table of Contents
Sketches in the SunRodger L. Patiencepage 3
Reflecting PoolRob Montgomerypage 5
Grandpa\u27s Porcelain DollRichard E. Hallpage 6
Tintype 1837Catherine Friemannpage 6
PhotographSteven M. Beamerpage 7
Washerwoman\u27s SongBob Zordanipage 8
Scrambled Eggs for D.O.Lynne A. Rafoolpage 8
my mother would sayMonica Grothpage 9
Retired by His ChildrenDan Von Holtenpage 10
I am the oldestMonica Grothpage 11
Ice on WheatRob Montgomerypage 12
The Nature of the RoseTroy Mayfieldpage 12
Past NebraskaDan Hornbostelpage 13
Five Minute Jamaican VacationChristy Dunphypage 14
PhotographSteven M. Beamerpage 14
The Angry PoemChristy Dunphypage 15
Road UnfamiliarChristy Dunphypage 15
raised voicesMonica Grothpage 16
Old Ladies & MiniskirtsKara Shannonpage 17
FreakspeakBob Zordanipage 18
PortraitDan Von Holtenpage 18
Mobile VacuumKathleen L. Fairfieldpage 19
Rev. Fermus DickSteve Hagemannpage 20
PhotographSteven M. Beamerpage 21
What\u27s the Name of That Flower?Richard Jesse Davispage 22
RequestChristy Dunphypage 23
SketchPaul Seabaughpage 24
ExperiencedMarilyn Wilsonpage 26
Leaving: Two ViewsTina Phillipspage 27
AntaeusDan Von Holtenpage 28
Misogyny at 19J. D. Finfrockpage 29
A Mental CrippleSteve Hagemannpage 32
AssociationsRhonda Ealypage 33
Banana BreadGail Bowerpage 34
Bill and JackBradford B. Autenpage 35
After Image No. 2Rob Montgomerypage 35
VrrooomBeth Goodmanpage 36
Mr. Modern LoverMolly Maddenpage 36
TravelogueRodger L. Patiencepage 37
Down the HighwayJoan Sebastianpage 38
A Retread HeavenRob Montgomerypage 41
StuporDan Von Holtenpage 42
Love Poem After a Seizure in Your BedBob Zordanipage 43
PalsyChristy Dunphypage 44
Interview with Mr. MatthewsBob Zordanipage 45
Chasing Down Hot Air Balloons on a Sunday MorningRob Montgomerypage 48https://thekeep.eiu.edu/vehicle/1049/thumbnail.jp
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
Community capacity to acquire, assess, adapt, and apply research evidence: a survey of Ontario's HIV/AIDS sector
<p>Abstract</p> <p>Background</p> <p>Community-based organizations (CBOs) are important stakeholders in health systems and are increasingly called upon to use research evidence to inform their advocacy, program planning, and service delivery. To better support CBOs to find and use research evidence, we sought to assess the capacity of CBOs in the HIV/AIDS sector to acquire, assess, adapt, and apply research evidence in their work.</p> <p>Methods</p> <p>We invited executive directors of HIV/AIDS CBOs in Ontario, Canada (n = 51) to complete the Canadian Health Services Research Foundation's "Is Research Working for You?" survey.</p> <p>Findings</p> <p>Based on responses from 25 organizations that collectively provide services to approximately 32,000 clients per year with 290 full-time equivalent staff, we found organizational capacity to acquire, assess, adapt, and apply research evidence to be low. CBO strengths include supporting a culture that rewards flexibility and quality improvement, exchanging information within their organization, and ensuring that their decision-making processes have a place for research. However, CBO Executive Directors indicated that they lacked the skills, time, resources, incentives, and links with experts to acquire research, assess its quality and reliability, and summarize it in a user-friendly way.</p> <p>Conclusion</p> <p>Given the limited capacity to find and use research evidence, we recommend a capacity-building strategy for HIV/AIDS CBOs that focuses on providing the tools, resources, and skills needed to more consistently acquire, assess, adapt, and apply research evidence. Such a strategy may be appropriate in other sectors and jurisdictions as well given that CBO Executive Directors in the HIV/AIDS sector in Ontario report low capacity despite being in the enviable position of having stable government infrastructure in place to support them, benefiting from long-standing investment in capacity building, and being part of an active provincial network. CBOs in other sectors and jurisdictions that have fewer supports may have comparable or lower capacity. Future research should examine a larger sample of CBO Executive Directors from a range of sectors and jurisdictions.</p
The effect of a supplementary ('Gist-based') information leaflet on colorectal cancer knowledge and screening intention: a randomized controlled trial.
Guided by Fuzzy Trace Theory, this study examined the impact of a 'Gist-based' leaflet on colorectal cancer screening knowledge and intentions; and tested the interaction with participants' numerical ability. Adults aged 45-59 years from four UK general practices were randomly assigned to receive standard information ('The Facts', n = 2,216) versus standard information plus 'The Gist' leaflet (Gist + Facts, n = 2,236). Questionnaires were returned by 964/4,452 individuals (22 %). 82 % of respondents reported having read the information, but those with poor numeracy were less likely (74 vs. 88 %, p < .001). The 'Gist + Facts' group were more likely to reach the criterion for adequate knowledge (95 vs. 91 %; p < .01), but this was not moderated by numeracy. Most respondents (98 %) intended to participate in screening, with no group differences and no interaction with numeracy. The improved levels of knowledge and self-reported reading suggest 'The Gist' leaflet may increase engagement with colorectal cancer screening, but ceiling effects reduced the likelihood that screening intentions would be affected
Variability of Bio-Clinical Parameters in Chinese-Origin Rhesus Macaques Infected with Simian Immunodeficiency Virus: A Nonhuman Primate AIDS Model
BACKGROUND: Although Chinese-origin Rhesus macaques (Ch RhMs) infected with simian immunodeficiency virus (SIV) have been used for many years to evaluate the efficacy of AIDS vaccines and therapeutics, the bio-clinical variability of such a nonhuman primate AIDS model was so far not established. METHODOLOGY/PRINCIPAL FINDINGS: By randomizing 150 (78 male and 72 female) Ch RhMs with diverse MHC class I alleles into 3 groups (50 animals per group) challenged with intrarectal (i.r.) SIVmac239, intravenous (i.v.) SIVmac239, or i.v. SIVmac251, we evaluated variability in bio-clinical endpoints for 118 weeks. All SIV-challenged Ch RhMs became seropositive for SIV during 1-2 weeks. Plasma viral load (VL) peaked at weeks 1-2 and then declined to set-point levels as from week 5. The set-point VL was 30 fold higher in SIVmac239 (i.r. or i.v.)-infected than in SIVmac251 (i.v.)-infected animals. This difference in plasma VL increased overtime (>100 fold as from week 68). The rates of progression to AIDS or death were more rapid in SIVmac239 (i.r. or i.v.)-infected than in SIVmac251 (i.v.)-infected animals. No significant difference in bio-clinical endpoints was observed in animals challenged with i.r. or i.v. SIVmac239. The variability (standard deviation) in peak/set-point VL was nearly one-half lower in animals infected with SIVmac239 (i.r. or i.v.) than in those infected with SIVmac251 (i.v.), allowing that the same treatment-related difference can be detected with one-half fewer animals using SIVmac239 than using SIVmac251. CONCLUSION/SIGNIFICANCE: These results provide solid estimates of variability in bio-clinical endpoints needed when designing studies using the Ch RhM SIV model and contribute to the improving quality and standardization of preclinical studies
Why Are There Social Gradients in Preventative Health Behavior? A Perspective from Behavioral Ecology
Background: Within affluent populations, there are marked socioeconomic gradients in health behavior, with people of lower socioeconomic position smoking more, exercising less, having poorer diets, complying less well with therapy, using medical services less, ignoring health and safety advice more, and being less health-conscious overall, than their more affluent peers. Whilst the proximate mechanisms underlying these behavioral differences have been investigated, the ultimate causes have not. Methodology/Principal Findings: This paper presents a theoretical model of why socioeconomic gradients in health behavior might be found. I conjecture that lower socioeconomic position is associated with greater exposure to extrinsic mortality risks (that is, risks that cannot be mitigated through behavior), and that health behavior competes for people’s time and energy against other activities which contribute to their fitness. Under these two assumptions, the model shows that the optimal amount of health behavior to perform is indeed less for people of lower socioeconomic position. Conclusions/Significance: The model predicts an exacerbatory dynamic of poverty, whereby the greater exposure of poor people to unavoidable harms engenders a disinvestment in health behavior, resulting in a final inequality in health outcomes which is greater than the initial inequality in material conditions. I discuss the assumptions of the model, and it
Community-based knowledge transfer and exchange: Helping community-based organizations link research to action
<p>Abstract</p> <p>Background</p> <p>Community-based organizations (CBOs) are important stakeholders in health systems and are increasingly called upon to use research evidence to inform their advocacy, program planning, and service delivery efforts. CBOs increasingly turn to community-based research (CBR) given its participatory focus and emphasis on linking research to action. In order to further facilitate the use of research evidence by CBOs, we have developed a strategy for community-based knowledge transfer and exchange (KTE) that helps CBOs more effectively link research evidence to action. We developed the strategy by: outlining the primary characteristics of CBOs and why they are important stakeholders in health systems; describing the concepts and methods for CBR and for KTE; comparing the efforts of CBR to link research evidence to action to those discussed in the KTE literature; and using the comparison to develop a framework for community-based KTE that builds on both the strengths of CBR and existing KTE frameworks.</p> <p>Discussion</p> <p>We find that CBR is particularly effective at fostering a climate for using research evidence and producing research evidence relevant to CBOs through community participation. However, CBOs are not always as engaged in activities to link research evidence to action on a larger scale or to evaluate these efforts. Therefore, our strategy for community-based KTE focuses on: an expanded model of 'linkage and exchange' (<it>i.e</it>., producers and users of researchers engaging in a process of asking and answering questions together); a greater emphasis on both producing and disseminating systematic reviews that address topics of interest to CBOs; developing a large-scale evidence service consisting of both 'push' efforts and efforts to facilitate 'pull' that highlight actionable messages from community relevant systematic reviews in a user-friendly way; and rigorous evaluations of efforts for linking research evidence to action.</p> <p>Summary</p> <p>Through this type of strategy, use of research evidence for CBO advocacy, program planning, and service delivery efforts can be better facilitated and continually refined through ongoing evaluations of its impact.</p
Decoding the regulatory network of early blood development from single-cell gene expression measurements.
Reconstruction of the molecular pathways controlling organ development has been hampered by a lack of methods to resolve embryonic progenitor cells. Here we describe a strategy to address this problem that combines gene expression profiling of large numbers of single cells with data analysis based on diffusion maps for dimensionality reduction and network synthesis from state transition graphs. Applying the approach to hematopoietic development in the mouse embryo, we map the progression of mesoderm toward blood using single-cell gene expression analysis of 3,934 cells with blood-forming potential captured at four time points between E7.0 and E8.5. Transitions between individual cellular states are then used as input to develop a single-cell network synthesis toolkit to generate a computationally executable transcriptional regulatory network model of blood development. Several model predictions concerning the roles of Sox and Hox factors are validated experimentally. Our results demonstrate that single-cell analysis of a developing organ coupled with computational approaches can reveal the transcriptional programs that underpin organogenesis.We thank J. Downing (St. Jude Children's Research Hospital, Memphis, TN, USA) for the Runx1-ires-GFP mouse. Research in the authors' laboratory is supported by the Medical Research Council, Biotechnology and Biological Sciences Research Council, Leukaemia and Lymphoma Research, the Leukemia and Lymphoma Society, Microsoft Research and core support grants by the Wellcome Trust to the Cambridge Institute for Medical Research and Wellcome Trust - MRC Cambridge Stem Cell Institute. V.M. is supported by a Medical Research Council Studentship and Centenary Award and S.W. by a Microsoft Research PhD Scholarship.This is the accepted manuscript for a paper published in Nature Biotechnology 33, 269–276 (2015) doi:10.1038/nbt.315
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