1,697 research outputs found

    Dielectric microscopy with submillimeter resolution

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    In analogy with optical near-field scanning methods, we use tapered dielectric waveguides as probes for a millimeter wave vector network analyzer. By scanning thin samples between two such probes we are able to map the spatially varying dielectric properties of materials with sub-wavelength resolution; using a 150 GHz probe in transmision mode we see spatial resolution of around 500 microns. We have applied this method to a variety of highly heterogeneous materials. Here we show dielectric maps of granite and oil shale

    Is the project management field suffering from methodological inertia? Looking for evidence in publications in a recently established journal

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    Project management (PM) researchers have traditionally used quantitative methods in their research due to the origins of this practice-based discipline in defence and engineering. Although qualitative methods are starting to be used in PM research, most of the qualitative research reported tends to use case studies. Recently, there has been a call for PM researchers to use more novel methods to increase the variety of methods used by the researcher in the field contributing to its further development (Drouin, Muller and Sankaran 2013; Cameron, Sankaran and Scales 2015). A review of papers presented at the International Research Network on Organizing by Projects (IRNOP) conference in Berlin in 2009 showed a surprising trend that papers presented at these conferences used more qualitative methods in comparison with articles published in key PM journals. This paper analyses articles published over the past six years in a comparatively new PM journal, since its inception, to explore whether the new journal has motivated PM researchers to overcome their methodological inertia and broaden the variety of research methods they use. A mixed methods prevalence study was undertaken on articles published in the International Journal of Managing Projects in Business (IJMPiB) from 2008 to 2014 (n=265). The findings point to methodological inertia in the majority of research but also an unusually high proportion of the use of mixed methods. Future research is needed to add finer granularity to the analysis

    The microbiome in wound repair and tissue fibrosis

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    Bacterial colonization occurs in all wounds, chronic or acute, and the break in epithelium integrity that defines a wound impairs the forces that shape and constrain the microbiome at that site. This review highlights the interactions between bacterial communities in the wound and the ultimate resolution of the wound or development of fibrotic lesions. Chronic wounds support complex microbial communities comprising a wide variety of bacterial phyla, genera, and species, including some fastidious anaerobic bacteria not identified using culture‐based methods. Thus, the complexity of bacterial communities in wounds has historically been underestimated. There are a number of intriguing possibilities to explain these results that may also provide novel insights into changes and adaptation of bacterial metabolic networks in inflamed and wounded mucosa, including the critical role of biofilm formation. It is well accepted that the heightened state of activation of host cells in a wound that is driven by the microbiota can certainly lead to detrimental effects on wound regeneration, but the microbiota of the wound may also have beneficial effects on wound healing. Studies in experimental systems have clearly demonstrated a beneficial effect for members of the gut microbiota on regulation of systemic inflammation, which could also impact wound healing at sites outside the gastrointestinal tract. The utilization of culture‐independent microbiology to characterize the microbiome of wounds and surrounding mucosa has raised many intriguing questions regarding previously held notions about the cause and effect relationships between bacterial colonization and wound repair and mechanisms involved in this symbiotic relationship.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95009/1/path4118.pd

    Convergent validity of ratings of perceived exertion during resistance exercise in healthy participants: A systematic review and meta-analysis

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    Background: The validity of ratings of perceived exertion (RPE) during aerobic training is well established; however, it’s validity during resistance exercise is less clear. This meta-analysis used the known relationships between RPE and exercise intensity (EI), heart rate (HR), blood lactate (BLa), blood pressure (BP) and electromyography (EMG) to determine the convergent validity of RPE as a measure of resistance exercise intensity and physiological exertion, during different forms of resistance exercise. Additionally, this study aims to assess the effect of several moderator variables on the strength of the validity coefficients, so that clearer guidance can be given on the use of RPE during resistance exercise. Methods: An online search of 4 databases and websites (PubMed, Web of science, SPORT Discus and Research Gate) was conducted up to 28 February 2020. Additionally, the reference lists of the included articles were inspected manually for further unidentified studies. The inclusion criteria were; healthy participants of any age, a rating scale used to measure RPE, resistance exercise of any type, one cohort receiving no other intervention, and must present data from one of the following outcome measures: EI, HR, BP, EMG or BLa. Weighted mean effect sizes (r) were calculated using a random-effects model. Heterogeneity was assessed using the Tau2 and I2 statistics. Moderator analysis was conducted using random-effects meta-regression. Results: One-hundred and eighteen studies were included in the qualitative synthesis, with 75 studies (99 unique cohorts) included in the meta-analysis. The overall weighted mean validity coefficient was large (0.88; 95% CI 0.84 to 0.91) and between studies heterogeneity was very large (Tau2 = 0.526, I2 = 96.1%). Studies using greater workload ranges, isometric muscle actions, and those that manipulated workload or repetition time, showed the highest validity coefficients. Conversely, sex, age, training status, RPE scale used, and outcome measure did not have an effect. Conclusions: RPE provides a valid measure of exercise intensity and physiological exertion during resistance exercise, with effect sizes comparable or greater than those shown during aerobic exercise. Therefore, RPE may provide an easily accessible means of prescribing and monitoring resistance exercise training. Registration: The systematic review protocol was registered on the PROSPERO database (CRD42018102640)

    Sources of variability in the prospective relation of language to social, emotional, and behavior problem symptoms: Implications for developmental language disorder

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    Children with developmental language disorder (DLD) are at risk for social, emotional, and behavioral (SEB) maladjustment throughout development, though it is unclear if poor language proficiency per se can account for this risk as associations between language and SEB appear more variable among typical-language children. This study investigated whether the relationship between language and SEB problems is stronger at very low levels of language and considered confounders including socioeconomic status, sex, and nonverbal intelligence. These were examined using a population-based survey design, including children with a wide range of language and cognitive profiles, and assessed using the Strengths and Difficulties Questionnaire and six standardized language measures (n = 363, weighted n = 6,451). Structural equation models adjusted for prior levels of SEB revealed that the relationship of language at age 5–6 years to SEB at 7–9 years was nonlinear. Language more strongly predicted all clusters of SEB at disordered language levels relative to typical language levels, with standardized betas of −.25 versus .03 for behavioral, −.31 versus −.04 for peer, and .27 versus .03 for prosocial problems. Wald tests between these pairs of betas yielded p values from .049 to .014. Sex moderated the nonlinear association between language and emotional symptoms. These findings indicate a clinical need to support language development in order to mitigate against problems of SEB and to carefully monitor the mental health needs of children with DLD, particularly in the context of multiple, and potentially sex-specific, risks

    Use of DNA Barcoding Combined with PCR-SFLP to Authenticate Species in Bison Meat Products

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    American bison (Bison bison) meat is susceptible to species mislabeling due to its high value and similar appearance to meat from domestic cattle (Bos taurus). DNA barcoding is commonly used to identify animal species. However, as a result of the historical hybridization of American bison and domestic cattle, additional genetic testing is required for species confirmation. The objective of this study was to perform a market survey of bison meat products and verify the species using DNA barcoding combined with polymerase chain reaction-satellite fragment length polymorphism (PCR-SFLP). Bison products (n = 45) were purchased from a variety of retailers. Samples that were positive for domestic cattle with DNA barcoding were further analyzed with PCR-SFLP. DNA barcoding identified bison in 41 products, red deer (Cervus elaphus) in one product, and domestic cattle in three products. PCR-SFLP confirmed the identification of domestic cattle in two samples, while the third sample was identified as bison with ancestral cattle DNA. Overall, mislabeling was detected in 3 of the 45 samples (6.7%). This study revealed that additional DNA testing of species that have undergone historical hybridization provides improved identification results compared to DNA barcoding alone

    Identification of a WNT5A-Responsive Degradation Domain in the Kinesin Superfamily Protein KIF26B.

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    Noncanonical WNT pathways function independently of the β-catenin transcriptional co-activator to regulate diverse morphogenetic and pathogenic processes. Recent studies showed that noncanonical WNTs, such as WNT5A, can signal the degradation of several downstream effectors, thereby modulating these effectors' cellular activities. The protein domain(s) that mediates the WNT5A-dependent degradation response, however, has not been identified. By coupling protein mutagenesis experiments with a flow cytometry-based degradation reporter assay, we have defined a protein domain in the kinesin superfamily protein KIF26B that is essential for WNT5A-dependent degradation. We found that a human disease-causing KIF26B mutation located at a conserved amino acid within this domain compromises the ability of WNT5A to induce KIF26B degradation. Using pharmacological perturbation, we further uncovered a role of glycogen synthase kinase 3 (GSK3) in WNT5A regulation of KIF26B degradation. Lastly, based on the identification of the WNT5A-responsive domain, we developed a new reporter system that allows for efficient profiling of WNT5A-KIF26B signaling activity in both somatic and stem cells. In conclusion, our study identifies a new protein domain that mediates WNT5A-dependent degradation of KIF26B and provides a new tool for functional characterization of noncanonical WNT5A signaling in cells

    Statin therapy in critical illness : an international survey of intensive care physicians' opinions, attitudes and practice

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    Background Pleotropic effects of statins on inflammation are hypothesised to attenuate the severity of and possibly prevent the occurrence of the host inflammatory response to pathogen and infection-related acute organ failure. We conducted an international survey of intensive care physicians in Australia, New Zealand (ANZ) and United Kingdom (UK). The aims of the survey were to assess the current prescribing practice patterns, attitudes towards prescribing statin therapy in critically ill patients and opinions on the need for an interventional trial of statin therapy in critically ill patients. Methods Survey questions were developed through an iterative process. An expert group reviewed the resulting 26 items for face and content validity and clarity. The questions were further refined following pilot testing by ICU physicians from Australia, Canada and the UK. We used the online Smart SurveyTM software to administer the survey. Results Of 239 respondents (62 from ANZ and 177 from UK) 58% worked in teaching hospitals; most (78.2%) practised in ‘closed’ units with a mixed medical and surgical case mix (71.0%). The most frequently prescribed statins were simvastatin (77.6%) in the UK and atorvastatin (66.1%) in ANZ. The main reasons cited to explain the choice of statin were preadmission prescription and pharmacy availability. Most respondents reported never starting statins to prevent (65.3%) or treat (89.1%) organ dysfunction. Only a minority (10%) disagreed with a statement that the risks of major side effects of statins when prescribed in critically ill patients were low. The majority (84.5%) of respondents strongly agreed that a clinical trial of statins for prevention is needed. More than half (56.5%) favoured rates of organ failure as the primary outcome for such a trial, while a minority (40.6%) favoured mortality. Conclusions Despite differences in type of statins prescribed, critical care physicians in the UK and ANZ reported similar prescription practices. Respondents from both communities agreed that a trial is needed to test whether statins can prevent the onset of new organ failure in patients with sepsis

    A tale of two sites: how inflammation can reshape the microbiomes of the gut and lungs

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141495/1/jlb0943.pd
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