The Effects of Fatty Desposits on the Accuracy of the Fibroscan Liver Transient Elastography Ultrasound System

A new generation of ultrasound transient elastography (TE) systems have emerged which exploit the well-known correlation between the liver’s pathological and mechanical properties through measurements of the Young’s elastic modulus; however, little work has been carried out to examine the effect that fatty deposits may have on the TE measurement accuracy. An investigation was carried out on the effects on the measurement accuracy of a transient elastography ultrasound system, the Fibroscan®, caused by overlaying fat layers of varying thickness on healthy liver-mimicking phantoms, simulating in vivo conditions for obese patients. Furthermore, a steatosis effect similar to that in non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD) was simulated to investigate its effect on the TE system. A range of novel elastography fat-mimicking materials were developed using 6-10wt% poly(vinyl alcohol) cryogel capable of achieving a range of acoustic velocities (1482-1530m/s) and attenuation coefficients (0.4-1dB/MHz/cm) for simulating different liver states. Laboratory-based acoustic velocities and attenuation coefficients were measured while the Young’s modulus was established through a gold standard compression testing method. A significant variation of the Young’s elastic modulus was measured in healthy phantoms with overlaying fat layers of thicknesses exceeding 45mm, impinging on the scanners region of interest, overestimating the compression tested values by up to 11kPa in some cases. Furthermore, Fibroscan® measurements of the steatosis phantoms showed a consistent overestimation (~54%), which strongly suggests that the speed of sound mismatch between that of liver tissue and that assumed by the scanner is responsible for the high clinical cut-offs established in the case of ALD and NAFLD

Evaluation of CIRS String Doppler Phantom as a Test Tool for Use in a Doppler Ultrasound Quality Assurance Program

Ultrasound Doppler systems are routinely used to perform blood flow velocity measurements which assist in the clinical assessment and diagnosis of vascular. Doppler measurements of peak velocities for vascular applications provide an indication of the degree of the stenosis which will ultimately assist in deciding how a patient is managed. It is imperative that Doppler systems are capable of accurately measuring blood flow velocities to ensure correct diagnosis and appropriate patient treatment; therefore such systems should be evaluated regularly as part of a Quality Assurance program. Although a range of Doppler test phantoms have been developed for quality control (QC) purposes to establish the measurement accuracy and stability of Doppler systems only a limited number of such test phantoms are commercially available, the easiest of these devices to operate is the String Phantom. Currently, only one string Doppler phantom is commercially available, namely the CIRS Model 043. In this study an evaluation of the performance of this test device was carried out as a number of problems currently exist with it such as the filament type, the fact that the filament passes through a water–air interface and vibrations from the motor. This study has established that the braided-silk filament, provided with the phantom, should not be used as it introduces errors of as much as 24% for the mean velocity accuracy and 20% for the intrinsic spectral broadening (ISB) depending on the soak time of the filament. Rather, to avoid such errors it is advised that the phantom be retrofitted with a filament made from an O-ring rubber. While this eliminates the temporal changes in backscatter seen with the braided-silk filament, further discrepancies were observed, even with an O-ring filament, when the filament velocity was set in the range 26–44 cm/s, where a resonance effect significantly increased the variability of the maximum velocity accuracy and ISB measurements. This was most likely as a result of the imposed vibrations from the motor, which is mounted directly onto the tank wall; hence, it would prove practical to avoid taking measurements in this velocity range where resonance effects are observed

Review of Ultrasound Elastography Quality Control and Training Test Phantoms

While the rapid development of ultrasound elastography techniques in recent decades has sparked its prompt implementation in the clinical setting adding new diagnostic information to conventional imaging techniques, questions still remain as to its full potential and efficacy in the hospital environment. A limited number of technical studies have objectively assessed the full capabilities of the different elastography approaches, perhaps due, in part, to the scarcity of suitable tissue-mimicking materials and appropriately designed phantoms available. Few commercially-available elastography phantoms possess the necessary test target characteristics or mechanical properties observed clinically, or indeed reflect the lesion-to-background elasticity ratio encountered during clinical scanning. Thus, while some phantoms may prove useful, they may not fully challenge the capabilities of the different elastography technniques, proving limited when it comes to quality control (QC) and/or training purposes. Although a variety of elastography tissue-mimicking materials, such as agar and gelatine dispersions, co-polymer in oil and poly(vinyl) alcohol cryogel, have been developed for specific research purposes, such work has yet to produce appropriately designed phantoms to adequately challenge the variety of current commercially-available elastography applications. Accordingly, there is a clear need for the further development of elastography TMMs and phantoms to keep pace with the rapid developments in elastography technology, to ensure the performance of these new diagnostic approaches are validated, and for clinical training purposes

Myc-binding Protein Orthologue Interacts with AKAP240 In the Central Pair Apparatus of the \u3cem\u3eChlamydomonas\u3c/em\u3e Flagella

Background Flagella and cilia are fine thread-like organelles protruding from cells that harbour them. The typical ‘9 + 2’ cilia confer motility on these cells. Although the mechanistic details of motility remain elusive, the dynein-driven motility is regulated by various kinases and phosphatases. A-kinase anchoring proteins (AKAPs) are scaffolds that bind to a variety of such proteins. Usually, they are known to possess a dedicated domain that in vitro interacts with the regulatory subunits (RI and RII) present in the cAMP-dependent protein kinase (PKA) holoenzyme. These subunits conventionally harbour contiguous stretches of a.a. residues that reveal the presence of the Dimerization Docking (D/D) domain, Catalytic interface domain and cAMP-Binding domain. The Chlamydomonas reinhardtii flagella harbour two AKAPs; viz., the radial spoke AKAP97 or RSP3 and the central pair AKAP240. Both these were identified on the basis of their RII-binding property. Interestingly, AKAP97 binds in vivo to two RII-like proteins (RSP7 and RSP11) that contain only the D/D domain. Results We found a Chlamydomonas Flagellar Associated Protein (FAP174) orthologous to MYCBP-1, a protein that binds to organellar AKAPs and Myc onco-protein. An in silico analysis shows that the N-terminus of FAP174 is similar to those RII domain-containing proteins that have binding affinities to AKAPs. Binding of FAP174 was tested with the AKAP97/RSP3 using in vitro pull down assays; however, this binding was rather poor with AKAP97/RSP3. Antibodies were generated against FAP174 and the cellular localization was studied using Western blotting and immunoflourescence in wild type and various flagella mutants. We show that FAP174 localises to the central pair of the axoneme. Using overlay assays we show that FAP174 binds AKAP240 previously identified in the C2 portion of the central pair apparatus. Conclusion It appears that the flagella of Chlamydomonas reinhardtii contain proteins that bind to AKAPs and except for the D/D domain, lack the conventional a.a. stretches of PKA regulatory subunits (RSP7 and RSP11). We add FAP174 to this growing list

Evaluate the Effectiveness of Information, Education and Communication Package on Knowledge and Knowledge on Practice Regarding Self Care among Mothers with Gestational Diabetes Mellitus in Selected Maternity Hospital at Trichy

A study to evaluate the effectiveness of Information, Education and Communication package on knowledge and knowledge on practice regarding self care among mothers with gestational diabetes mellitus in selected maternity hospital at Trichy District. The present study was conducted in Pankajam hospital and Jagatha hospital at Trichy District. Pre-experimental one group pretest posttest design was used for this study. Permission was obtained from the medical superintendent and data collection was done over a period of 4 weeks. The investigator had selected 30 mothers with gestational diabetes mellitus through convenience sampling technique. Oral consent was obtained. Pretest was done on day first with structured knowledge questionnaire to assess the level of knowledge and check list was used to assess the level of knowledge on practice. Then Information, Education and Communication package was administered to the subjects with video clippings, Pamphlet and demonstration for 20 minutes. The posttest knowledge and knowledge on practice of the subjects were assessed after 15 days with the help of same questionnaire. Descriptive and inferential statistics were used to analysis the findings of the study. There was significant difference found (P<0.05) on knowledge and knowledge on practice. The mean knowledge score during pre test was 10.4(±2.26) and post test was 18.9(±1.46), the mean score of knowledge on practice during pre test was 3.56(±1.28)and post test was 8.2(±1.166). There was a positive correlation found between post test level of knowledge score and knowledge on practice score(r=0.9). There was a significant association found( P<0.05) between the selected demographic variables such as mothers age, educational status, place of residence, age at marriage, number of children, antenatal check up, previous history of abortion, treatment for gestational diabetes mellitus with posttest level of knowledge. There was a significant association found (P<0.05) between educational status, antenatal check up, family history of diabetes mellitus, treatment for gestational diabetes mellitus with posttest level of knowledge on practice. It is concluded that Information, Education and Communication Package is an effective tool in creating awareness to all antenatal mothers which bring down the maternal mortality and also prevents the maternal and fetal complications

Effects of Asymmetric Information on Market Timing in the Mutual Fund Industry

Purpose The purpose of this paper is to investigate the effects of information asymmetry (between the realized return and the expected return) on market timing in the mutual fund industry. Design/methodology/approach For the purpose, the authors use a panel of 1,488 active open-end mutual funds for the period 2004-2013. The authors use fund-specific time-dynamic betas. The information asymmetry is measured as the standard deviation of idiosyncratic risk. The data set is decomposed into five market fundamentals in order to emphasis the policy implications of the findings with respect to: equity, fixed income, allocation, alternative, and tax-preferred mutual funds. The empirical evidence is based on endogeneity-robust difference and system generalized method of moments. Findings The following findings are established. First, the information asymmetry broadly follows the same trend as volatility, with a higher sensitivity to market risk exposure. Second, fund managers tend to raise (cutback) their risk exposure in time of high (low) market liquidity. Third, there is evidence of convergence in equity funds. The authors may, therefore, infer that equity funds with lower market risk exposure are catching-up with their counterparts with higher exposure to fluctuation in market conditions. Originality/value The paper complements the sparse literature on market timing in the mutual fund industry with time-dynamic betas, information asymmetry and an endogeneity-robust empirical approac

Innovations in savings behaviour and agricultural business support for women: The Ghanaian ‘Money-Box’

In Ghana, like many African countries, women are financially disadvantaged compared to men, which has encouraged women to form credit associations. This paper examined the “Pagwuni” Women’s Group (PWG) in the Northern region of Ghana, where over 93 percent of members are smallholder farmers. Women make regular membership and social fund contributions with records kept in a secured ‘money-box’, opened at an agreed time. Members receive their money according to the amount contributed while the ‘social fund’ is for purchasing farm inputs. This study analysed the effect of the Pagwuni Women Group (PWG) financing activities on the financial needs of the group and their households’ economic welfare. The study also examined the kind of innovation that this PWG adopts that differs from the traditional Village Savings and Loans Association (VSLA). In investigating the sustainability of this ‘money-box’ model, data was sourced from 150 participants and the group administrators using a mixed research method. Three significant findings were uncovered. First, 93.3 percent of the respondents are peasant farmers. Second, 86.7percent indicated that this money-box arrangement is their only form of savings. Hence, since PWG is a woman-only group, it offers a good opportunity to understand the interconnections between gender and the economic welfare, enhancing the potential benefits of such group savings associations. Third, access to the social fund component of money-box helped the female participants to acquire the equipment and services needed to modernise their farming activities. Policy recommendations to link such rural money box initiatives with formal financial institutions to help channel funds to small-scale female farmers are discussed. (Afr J Reprod Health 2021; 25[5s]: 147-158)

Broadband Acoustic Measurement of the Agar-based Tissue Mimicking Material: a Longitudinal Study

Commercially available ultrasound quality assurance test phantoms rely on the long-term acoustic stability of the tissue-mimicking-material (TMM). Measurement of the acoustic properties of the TMM can be technically challenging, and it is important to ensure its stability. The standard technique is to film-wrap samples of TMM and to measure the acoustic properties in a water bath. In this study, a modified technique was proposed whereby the samples of TMM are measured in a preserving fluid that is intended to maintain their characteristics. The acoustic properties were evaluated using a broadband pulse-echo substitution technique over the frequency range 4.5–50 MHz at 0, 6 and 12 months using both techniques. For both techniques, the measured mean values for the speed of sound and attenuation were very similar and within the International Electrotechnical Commission-recommended value. However, the results obtained using the proposed modified technique exhibited greater stability over the 1-y period compared with the results acquired using the standard technique

First description of a Shiga toxin-producing Escherichia coli O103:H2 strain isolated from sheep in Brazil

Univ Estadual Londrina, Dept Microbiol, Londrina, BrazilUniversidade Federal de São Paulo, Dept Microbiol Parasitol & Imunol, São Paulo, BrazilInst Butantan, Bacteriol Lab, São Paulo, BrazilUniv Santiago de Compostela, Fac Vet, Dept Microbiol & Parasitol, Lab Referencia E Coli, Lugo, SpainUniversidade Federal de São Paulo, Dept Microbiol Parasitol & Imunol, São Paulo, BrazilWeb of Scienc

Human Rad52 binding renders ssDNA unfolded: image and contour length analyses by Atomic Force Microscopy

Atomic force microscopy imaging has been used to study the changes associated with human Rad52 (HsRad52) protein in solution, in dried state as well as following ssDNA (linear and circular) binding. In the dried state, the free protein exists predominantly as a characteristic panoply of novel trifoliate forms. However, in solution, the level of trifoliates diminishes significantly. Height analyses of either form reveal two categories: smaller (~ 3-5 nm) and larger ((~ 10-12 nm) particles, perhaps related to sub-heptameric and heptameric forms respectively. Interestingly, binding of the protein to linear ssDNA smoothly extends and unfolds the naked DNA. Contour length measurements performed on several individual circular ssDNA/nucleoprotein complexes reveal marked (about threefold) extension of naked ssDNA, following HsRad52 binding. We speculate that the alignment of HsRad52 on ssDNA into a smoothly extended and unfolded strand from that of highly compact morphology of naked ssDNA, may have bearing on the recombination function of HsRad52 protein