7,233 research outputs found

    Inhibition of translation by poliovirus: Inactivation of a specific initiation factor

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    Translation of vesicular stomatitis virus (VSV) mRNA, like host mRNA translation, is inhibited in cells infected with poliovirus. To study the mechanism of poliovirus-induced inhibition of protein synthesis, we prepared extracts from poliovirus-infected and uninfected HeLa cells. Poliovirus mRNA was translated in lysates from both infected and uninfected cells, while VSV mRNA was translated only in the lysate from uninfected cells. Addition of purified translation initiation factors to the extract from infected cells showed that one factor, eIF-4B, could restore VSV mRNA translation in the infected lysate, but did not increase poliovirus mRNA translation. Further experiments involving translation of VSV mRNA in mixed extracts from poliovirus-infected and uninfected cells showed (i) that there was not an excess of an inhibitor of VSV mRNA translation in the infected lysate, but (ii) that an activity that caused a slow inactivation of eIF-4B was present in the infected lysate. Inactivation of eIF-4B appears to be the mechanism by which poliovirus infection causes a selective inhibition of translation

    Institutions and the Volatility Curse

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    This paper revisits the resource curse paradox and studies the impact of resource rents and their volatility on economic growth under varying institutional quality. Using five-year non-overlapping observations between 1970 and 2005 for 112 countries, we find that while resource rents enhance real output per capita, their volatility exerts a negative impact on economic growth. Therefore, we argue that volatility, rather than abundance per se, drives the resource curse. However, we also find that higher institutional quality can help offset some of the negative volatility effects of resource rents. Therefore, resource abundance can be a blessing provided that growth and welfare enhancing policies and institutions are adopted

    Testing Alternative Theories of the Property Price-Trading Volume Correlation

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    This article examines the correlation between the real housing price and trading volume. Contrary to the predictions of standard rational expectation models, a robust positive correlation between the two variables is identified. While no clear lead-lag relationship is found in the raw data, which is more consistent with the downpayment effect model, the medium-run component of the trading volume tends to lead (and Granger cause) the corresponding component of the property price, which is more consistent with the search theoretic model. An explanation for this difference in behavior is suggested and several future research directions are provided.

    High-Performance Bioinstrumentation for Real-Time Neuroelectrochemical Traumatic Brain Injury Monitoring

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    Traumatic brain injury (TBI) has been identified as an important cause of death and severe disability in all age groups and particularly in children and young adults. Central to TBIs devastation is a delayed secondary injury that occurs in 30–40% of TBI patients each year, while they are in the hospital Intensive Care Unit (ICU). Secondary injuries reduce survival rate after TBI and usually occur within 7 days post-injury. State-of-art monitoring of secondary brain injuries benefits from the acquisition of high-quality and time-aligned electrical data i.e., ElectroCorticoGraphy (ECoG) recorded by means of strip electrodes placed on the brains surface, and neurochemical data obtained via rapid sampling microdialysis and microfluidics-based biosensors measuring brain tissue levels of glucose, lactate and potassium. This article progresses the field of multi-modal monitoring of the injured human brain by presenting the design and realization of a new, compact, medical-grade amperometry, potentiometry and ECoG recording bioinstrumentation. Our combined TBI instrument enables the high-precision, real-time neuroelectrochemical monitoring of TBI patients, who have undergone craniotomy neurosurgery and are treated sedated in the ICU. Electrical and neurochemical test measurements are presented, confirming the high-performance of the reported TBI bioinstrumentation

    Stress Urinary Incontinence post-Holmium Laser Enucleation of the Prostate: a Single-Surgeon Experience.

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    PURPOSE: To identify incidence and predictors of stress urinary incontinence (SUI) following Holmium laser enucleation of the prostate (HoLEP). MATERIALS AND METHODS: We performed a retrospective review of 589 HoLEP patients from 2012-2018. Patients were assessed at pre-operative and post-operative visits. Univariate and multivariate regression analyses were performed to identify predictors of SUI. RESULTS: 52/589 patients (8.8%) developed transient SUI, while 9/589 (1.5%) developed long-term SUI. tSUI resolved for 46 patients (88.5%) within the first six weeks and in 6 patients (11.5%) between 6 weeks to 3 months. Long-term SUI patients required intervention, achieving continence at 16.4 months on average, 44 men (70.9%) with incontinence were catheter dependent preoperatively. Mean prostatic volume was 148.7mL in tSUI patients, 111.6mL in long-term SUI, and 87.9mL in others (p \u3c 0.0001). On univariate analysis, laser energy used (p \u3c 0.0001), laser on time (p=0.0204), resected prostate weight (p \u3c 0.0001), overall International Prostate Symptom Score (IPSS) (p=0.0005), and IPSS QOL (p=0.02) were associated with SUI. On multivariate analysis, resected prostate weight was predictive of any SUI and tSUI, with no risk factors identified for long-term SUI. CONCLUSION: Post-HoLEP SUI occurs in ~10% of patients, with 1.5% continuing beyond six months. Most patients with tSUI recover within the first six weeks. Prostate size \u3e100g and catheter dependency are associated with increased risk tSUI. Larger prostate volume is an independent predictor of any SUI, and tSUI

    Local anaesthesia systemic toxicity (LAST) – A stroke mimicker

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    Local anaesthesia systemic toxicity (LAST) is an uncommon and a potentially life-threatening event that develops after peripheral nerve block. The cause may be multifactorial and may include the choice of drug, technique of block and individual patient risk factors. We report a case of a 55-year-old female who developed slurring of speech and quadriplegia after receiving a mixture of lignocaine and hydrocortisone through an intra-articular injection to the right shoulder. Neurological examination revealed hypotonia and absence of power (0/5) in all limbs. These toxic events may have resulted from an accidental intra-arterialor dural cuff injection of local anaesthesia or absorption from surrounding tissues. This case report demonstrated that an intra-articular injection in the shoulder may cause LAST and may be under-recognized as it can mimic stroke

    Positioning analysis of multiple antennas in a dense RFID reader environment

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    ©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.The study and analysis of RFID antenna positioning is important for supply chain large-scale deployment. In a dense reader environment, there will be multiples of RFID readers and readers interference will reduce the reliability and efficiency of the RFID system. In the worst case, the interference would paralyse an entire RFID system. This paper explores antenna positioning in an RFID deployment zone and aims to provide guidelines on safe distance between antennas in a dense reader environment or even in a "Listen Before Talk" regulated area. By planning of antenna positioning, a RFID system can be optimised and its interference to other RF systems in the surroundings can be minimised. All the simulations results presented in this paper are obtained using MATLAB.Kin Seong Leong, Mun Leng Ng, Peter H. Col

    Evidence for internal electric fields in two variant ordered GaInP obtained by scanning capacitance microscopy

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    Journal ArticleSingle and two variant ordered GaInP samples are studied in cross section with the scanning capacitance microscope. Our study shows significant differences in the electronic properties of single and two variant GaInP. In unintentionally doped, ordered two variant samples, both n and p-type like domains are observed with the scanning capacitance microscope. In contrast, a spatially uniform capacitance signal is observed in unintentionally doped single variant ordered GaInP. These microscopic capacitance observations can be qualitatively explained by bend bending or internal electric fields

    Shear force microscopy with capacitance detection for near-field scanning optical microscopy

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    Journal ArticleShear force microscopy is very useful for distance regulation in near-field scanning optical microscopy (NSOM). However, the optical method used to detect the shear force can cause problems when imaging photosensitive materials, i.e., the shear force detection beam can optically pump the sample. We present here a new approach to shear force detection based upon capacitance sensing. The design, operation, and performance of the capacitance detection are presented. Shear force topographic images of hard and soft surfaces are shown using tungsten and NSOM fiber tips. The closed loop vertical sensitivity achieved is 0.01 nm//Hz

    Spatial mapping of ordered and disordered domains of GaInP by near-field scanning optical microscopy and scanning capacitance microscopy

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    Journal ArticleImaging of topography, locally induced photoluminescence and Fermi-level pinning in adjacent ordered and disordered domains on a cleaved GaInP sample is performed using a near-field scanning optical microscope and scanning capacitance microscope at room temperature in air. Highly localized photoluminescence spectra obtained by the near-field scanning optical microscope on these domains show spectral peaks at 680 nm (ordered) and 648 nm (disordered) GaInP. The near-field scanning optical microscope and scanning capacitance microscope data confirm previously published data, indicating that the electronic surface structure of ordered GaInP is significantly different from that of disordered GaInP. Both approaches indicate that the Fermi-level at the surface of ordered GaInP is pinned, while the Fermi-level at the surface of disordered GaInP is not pinned. The size, structure, and position of the ordered and disordered domains observed by the near-field scanning optical microscope and scanning capacitance microscope agree with those obtained by cathodoluminescence and Kelvin probe force microscop
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