1,639 research outputs found

    Global analyses of endonucleolytic cleavage in mammals reveal expanded repertoires of cleavage-inducing small RNAs and their targets.

    Get PDF
    In mammals, small RNAs are important players in post-transcriptional gene regulation. While their roles in mRNA destabilization and translational repression are well appreciated, their involvement in endonucleolytic cleavage of target RNAs is poorly understood. Very few microRNAs are known to guide RNA cleavage. Endogenous small interfering RNAs are expected to induce target cleavage, but their target genes remain largely unknown. We report a systematic study of small RNA-mediated endonucleolytic cleavage in mouse through integrative analysis of small RNA and degradome sequencing data without imposing any bias toward known small RNAs. Hundreds of small cleavage-inducing RNAs and their cognate target genes were identified, significantly expanding the repertoire of known small RNA-guided cleavage events. Strikingly, both small RNAs and their target sites demonstrated significant overlap with retrotransposons, providing evidence for the long-standing speculation that retrotransposable elements in mRNAs are leveraged as signals for gene targeting. Furthermore, our analysis showed that the RNA cleavage pathway is also present in human cells but affecting a different repertoire of retrotransposons. These results show that small RNA-guided cleavage is more widespread than previously appreciated. Their impact on retrotransposons in non-coding regions shed light on important aspects of mammalian gene regulation

    Stability of candida albicans over long and short term storage in a resource-limited setting

    Get PDF
    BACKGROUND: Candida albicans are widely isolated fungal yeast agents from clinical samples. Several storage methods for fungi have evolved overtime and they are not without setbacks. Preservation method is critical for research,training and teaching.In resource–poor setting,the method to employ must be cheap and easy to maintain with minimal risk of contamination as well as degeneration of the organisms.We thus,set out to study the stability of Candida albicans over long and short term storage in a resource-limited setting.METHODS: One hundred Candida albicans strains isolated from patients with vulvovaginal candidiasis and oral candidiasis were preserved in triplicates using sterile distilled water,Chromagar plate,mineral oil overlay and brain heart infusion broth plus 10% glycerol at -20OC.Recovery rates were determined at six months,12 months and 18 months by sub-culturing onto sabouraud dextrose agar.RESULT: The recovery rate of C. albicans was 100% for all the preservation methods used during the six months storage,mineral oil overlay and brain heart infusion broth plus 10% glycerol for the 12months storage,and only the brain heart infusion broth plus 10% glycerol during the 18months storage.CONCLUSION: Candida albicans can be preserved over long period of time in resource- limited setting where power supply is erratic using brain heart infusion broth plus 10% glycerol at -20OC and mineral oil overlay technique whereas for short term preservation, sterile distilled water and taped culture plates technique can be used. Preservation of Candida albicans isolates in resource- limited setting over short or long term period is possible and affordable depending on the technique employed.KEYWORDS: Candida albicans, preservation, sterile distilled water, Chromagar plate, mineral oil overlay, brain heart infusion broth

    Efficient visual object and word recognition relies on high spatial frequency coding in the left posterior fusiform gyrus: Evidence from a case-series of patients with ventral occipito-temporal cortex damage

    Get PDF
    Recent visual neuroscience investigations suggest that ventral occipito-temporal cortex is retinotopically organized, with high acuity foveal input projecting primarily to the posterior fusiform gyrus (pFG), making this region crucial for coding high spatial frequency information. Because high spatial frequencies are critical for fine-grained visual discrimination, we hypothesized that damage to the left pFG should have an adverse effect not only on efficient reading, as observed in pure alexia, but also on the processing of complex non-orthographic visual stimuli. Consistent with this hypothesis, we obtained evidence that a large case series (n = 20) of patients with lesions centered on left pFG: 1) Exhibited reduced sensitivity to high spatial frequencies; 2) demonstrated prolonged response latencies both in reading (pure alexia) and object naming; and 3) were especially sensitive to visual complexity and similarity when discriminating between novel visual patterns. These results suggest that the patients' dual reading and non-orthographic recognition impairments have a common underlying mechanism and reflect the loss of high spatial frequency visual information normally coded in the left pFG

    The dire disregard of measurement invariance testing in psychological science

    Get PDF
    In psychological science, self-report scales are widely used to compare means in targeted latent constructs across time points, groups, or experimental conditions. For these scale mean comparisons (SMC) to be meaningful and unbiased, the scales should be measurement invariant across the compared time points or (experimental) groups. Measurement invariance (MI) testing checks whether the latent constructs are measured equivalently across groups or time points. Since MI is essential for meaningful comparisons, we conducted a systematic review to check whether MI is taken seriously in psychological research. Specifically, we sampled 426 psychology articles with openly available data that involved a total of 918 SMCs to (1) investigate common practices in conducting and reporting of MI testing, (2) check whether reported MI test results can be reproduced, and (3) conduct MI tests for the SMCs that enabled sufficiently powerful MI testing with the shared data. Our results indicate that (1) 4% of the 918 scales underwent MI testing across groups or time and that these tests were generally poorly reported, (2) none of the reported MI tests could be successfully reproduced, and (3) of 161 newly performed MI tests, a mere 46 (29%) reached sufficient MI (scalar invariance), and MI often failed completely (89; 55%). Thus, MI tests were rarely done and poorly reported in psychological studies, and the frequent violations of MI indicate that reported group differences cannot be solely attributed to group differences in the latent constructs. We offer recommendations on reporting MI tests and improving computational reproducibility practices

    Survey of Farmers Market Managers in California: Food Safety Perspectives

    Get PDF
    We conducted a survey to characterize certified California farmers markets (FMs) regarding location, seasonality, size, product, product labeling, advertising methods, postharvest practices, regulations governing vendors, training offered, and training interests. Data obtained from the survey highlight the need for improvement regarding food safety and can serve as a basis for development of collaborative education by Extension educators, regulatory agencies, and FMs. Extension professionals can play a proactive role in such training opportunities, focusing outreach efforts for training according to applicable findings and including online training venues to maximize reach to stakeholders

    Imaging, Spectroscopy, Mechanical, Alignment and Biocompatibility Studies of Electrospun Medical Grade Polyurethane (Carbothaneâ„¢ 3575A) Nanofibers and Composite Nanofibers Containing Multiwalled Carbon Nanotubes

    Get PDF
    In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior of the prepared nanofiber mats and had a significant attachment of cells towards nanofibers. The incorporation of MWCNTs into polymeric nanofibers led to an improvement in tensile stress from 11.40 ± 0.9 to 51.25 ± 5.5 MPa. Furthermore, complete alignment of the nanofibers resulted in an enhancement on tensile stress to 72.78 ± 5.5 MPa. Displaying these attributes of high mechanical properties and non-toxic nature of nanofibers are recommended for an ideal candidate for future tendon and ligament grafts

    Definition of large bowel obstruction by primary colorectal cancer:A systematic review

    Get PDF
    Aim: Controversies on therapeutic strategy for large bowel obstruction by primary colorectal cancer mainly concern acute conditions, being essentially different from subacute obstruction. Clearly defining acute obstruction is important for design and interpretation of studies as well as for guidelines and daily practice. This systematic review aimed to evaluate definitions of obstruction by colorectal cancer in prospective studies. Method: A systematic search was performed in PubMed, Embase and the Cochrane Library. Eligibility criteria included randomized or prospective observational design, publication between 2000 and 2019, and the inclusion of patients with an obstruction caused by colorectal cancer. Provided definitions of obstruction were extracted with assessment of common elements. Results: A total of 16 randomized controlled trials (RCTs) and 99 prospective observational studies were included. Obstruction was specified as acute in 28 studies, complete/emergency in five, (sub)acute or similar terms in four and unspecified in 78. Five of 16 RCTs (31%) and 37 of 99 cohort studies (37%) provided a definition. The definitions included any combination of clinical symptoms, physical signs, endoscopic features and radiological imaging findings in 25 studies. The definition was only based on clinical symptoms in 11 and radiological imaging in six studies. Definitions included a radiological component in 100% of evaluable RCTs (5/5) vs. 54% of prospective observational studies (20/37, P = 0.07). Conclusion: In this systematic review, the majority of prospective studies did not define obstruction by colorectal cancer and its urgency, whereas provided definitions varied hugely. Radiological confirmation seems to be an essential component in defining acute obstruction
    • …
    corecore