Identification of two GH18 chitinase family genes and their use as targets for detection of the crayfish-plague oomycete Aphanomyces astaci

<p>Abstract</p> <p>Background</p> <p>The oomycete <it>Aphanomyces astaci </it>is regarded as the causative agent of crayfish plague and represents an evident hazard for European crayfish species. Native crayfish populations infected with this pathogen suffer up to 100% mortality. The existence of multiple transmission paths necessitates the development of a reliable, robust and efficient test to detect the pathogen. Currently, <it>A. astaci </it>is diagnosed by a PCR-based assay that suffers from cross-reactivity to other species. We developed an alternative closed-tube assay for <it>A. astaci</it>, which achieves robustness through simultaneous amplification of multiple functionally constrained genes.</p> <p>Results</p> <p>Two novel constitutively expressed members of the glycosyl hydrolase (GH18) gene family of chitinases were isolated from the <it>A. astaci </it>strain Gb04. The primary amino acid sequence of these chitinase genes, termed <it>CHI2 </it>and <it>CHI3</it>, is composed of an N-terminal signal peptide directing the post-translational transport of the protein into the extracellular space, the catalytic GH18 domain, a proline-, serine-, and threonine-rich domain and a C-terminal cysteine-rich putative chitin-binding site. The <it>A. astaci </it>mycelium grown in a pepton-glucose medium showed significant temporal changes in steady-state <it>CHI2 </it>and <it>CHI3 </it>mRNA amounts indicating functional constraint. Their different temporal occurrence with maxima at 48 and 24 hours of incubation for <it>CHI2 </it>and <it>CHI3</it>, respectively, is in accordance with the multifunctionality of GH18 family members. To identify <it>A. astaci</it>-specific primer target sites in these novel genes, we determined the partial sequence homologs in the related oomycetes <it>A. frigidophilus</it>, <it>A. invadans</it>, <it>A. helicoides</it>, <it>A. laevis</it>, <it>A. repetans</it>, <it>Achlya racemosa</it>, <it>Leptolegnia caudata</it>, and <it>Saprolegnia parasitica</it>, as well as in the relevant fungi <it>Fusarium solani </it>and <it>Trichosporon cutaneum</it>. An <it>A. astaci</it>-specific primer pair targeting the novel genes <it>CHI2 </it>and <it>CHI3 </it>as well as <it>CHI1 </it>- a third GH18 family member - was multiplexed with primers targeting the <it>5.8S rRNA </it>used as an endogenous control. A species was typed unambiguously as <it>A. astaci </it>if two peaks were concomitantly detected by melting curve analysis (MCA). For sensitive detection of the pathogen, but also for quantification of agent levels in susceptible crayfish and carrier crayfish, a TaqMan-probe based real-time PCR (qPCR) assay was developed. It targets the same chitinase genes and allows quantification down to 25 target sequences.</p> <p>Conclusion</p> <p>The simultaneous qualitative detection of multiple sequences by qPCR/MCA represents a promising approach to detect species with elevated levels of genetic variation and/or limited available sequence information. The homogenous closed-tube format, reduced detection time, higher specificity, and the considerably reduced chance of false negative detection achieved by targeting multiple genes (<it>CHI1</it>, <it>CHI2</it>, <it>CHI3</it>, and the endogenous control) at least two of which are subject to high functional constraint, are the major advantages of this multiplex assay compared to other diagnostic methods.</p> <p>Sensitive quantification achieved with TaqMan qPCR facilitates to monitor infection status and pathogen distribution in different tissues and can help prevent disease transmission.</p

Fetal Biometric Charts and Reference Equations for Pregnant Women Living in Port Said and Ismailia Governorates in Egypt

AIM: To construct new fetal biometric charts and equations for some fetal biometric parameters for women between 12th and 41st  weeks living in Ismailia and Port Said Governorates in Egypt.MATERIAL AND METHODS: This cross-sectional study was carried out on 656 Egyptian women (from Ismailia and Port Said governorates) with an uncomplicated pregnancy, and all were sure of their dates. The selected group was between the 12th and 41st weeks of gestation, recruited from the district general hospital in Ismailia and Port Said to measure ultrasonographically biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL), then for each measurement separate regression models were fitted to estimate both the mean and the Standard deviation at each gestational age.RESULTS: New Egyptian charts were reported for BPD, HC, AC, and FL. Reference equations for the dating of pregnancy were presented. The mean of the previous measurements at 12th and 41st weeks were as follows: (23.37, 98.72), (83.05, 336.12), (67.85, 332.57) and (12.50, 74.92) respectively.CONCLUSION: New fetal biometric charts and regression equations for pregnant women living in Port Said &amp; Ismailia governorates in Egypt

Um Saber, Shadia and my Self: The Power Relationship Between the Researched and the Researcher

[abstract not provided]https://fount.aucegypt.edu/faculty_book_chapters/2259/thumbnail.jp

Women in difficult circumstances An assessment of the impact of social policy and welfare programmes on female heads of households in low-income urban Egypt

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN026833 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

An investigation into the interfacial bond strength of the titanium - ceramic system for dental application

Failures that occur in titanium-ceramic restorations are of concem to dental clinicians. The formation of poorly adhering oxide on titanimu. at ceramic sinteling temperatures, causes adherence problems between titmlium <md ceranlic, wllich is the main limiting factor in the fabrication of titanium ceramic restoration. To overcome this problem tllis study investigated the effect of various surface treatments and cermuic types on the bond strength of tit<U1imu-ceranlic systcms and comparcd thcm to that of the Ni-Cr/ ceramic system. The following titmlimu surface treatmcnts wcre investigatcd:- polished, sandblasting with different grit size of 50, 125, 250Jlm, silicon dioxide and silicon rlitride coating, <Uld acid etching. Titmlium Ships were prepared, (n=15), following the protocol of ISO 9693:2000 mld divided into five study sections to make the comparison. The titanium-ceramic specimens were subjected to a three point flexural test. The groups were compared for their bond strength. SEM and SEMIEDS analyses were performed on the delanlinated titanium surfaces to ascertain bond failme. Section 1 investigated the effect of sUlface texture (s,mdblasting and polishing). A comparison between Nickel-Chromium alloy and titmlium to the appropriate ceranlic systems was made. The mean bond strength of sandblasted NickelShromium/ Vita VMK95, polished Ni-Cr/Vila VMK95, polished Titaruum/Vita VMK95 and 50Jlm sandblasted Titmlium/Vita VMK95 were 49.9-t±9.20, 44.13±7,47, 23.34±6.83, 39.15±5.17 MPa, respectively. The sandblasted Ni-Cr group was significantly higher tllan that of the other tested groups. The polished titmlium showed the lowest bond strengtll among the four groups. Section 2 evaluated, by means of a 3-point bendlllg test, the bond strcngtll of differcnt sandblasted titanium substratcs, (50Jlm, 125Jl111, 250Jlm), applied to three commercial low-fusing ceml1lic systems, (Vita Titankeranlik, Triceranl and Noritake). Noritake ceranuc had significantly higher bond strength than the other cemnlics. However, 110 significant difference v·,as found between Tricemm and Vita Titmlkeranuk. No significant difference was detected between the three smldblasting treaUuents (p=0.165). The bond sU'ength of the sandblasted TilNoritake groups (48.39-53.30) MPa was comparable to the smldblasted Ni- Crgroup. . Section 3 evaluated, by mean of a 3-point bending test, the bond strength of etched and coated titmlium substrates combined to Vita Titmlkeranlik ceranlic. The results showed that 10% acid etched Ti, polished Ti, and the polished/silicon sputtered Ti groups have the lowest flexural bond strength among all study groups. The flexural bond strength of the polished! Si3N4 sputtered Ti group was significantly Iligher (P<O.OO I) tllan Ilmt ofpolished Ti or polished! silicon spultered Ti groups. Section 4 investigated the eJIect of titarulUll specimens' preparation method; i.e. casting vs machining, on the fle:mral bond strcngth of ceranlic to titanium. The mean fleXtrral bond strength of the C<'lst Ti specimens was 44.17±II.9I MPa while the mean bond strength of the machined Ti was 43.33±6.72 MPa with a range between 26.94 to 53,41 MPa. No sigllificant difference between the cast <md machined groups was found (P= 0.696). Section 5 investigated the effect of thermocycling on the bond strength of the three cenmlics systems to titanium. The mean bond strength of non-thermocycled Ti/Vita Titankeranlik, Til Triceranl, and TilNoritake groups were 44.74±11.92, -l0.37±10.25, 52.28±5.31 MPa, respectively while the thcrmocycled groups were 38.6H7.7-l, 37.53±9.30 and 5I.I9±7AI MPa. respectively. Supplied by The British Library - 'The world's knowledge'EThOS - Electronic Theses Online ServiceGBUnited Kingdo

New local difference binary image descriptor and algorithm for rapid and precise vehicle visual localisation

Autonomous vehicle self‐localisation by scene matching under extreme environmental changes has been among the most challenging problems in robotics and computer vision in the last few years. Large dynamic illumination changes during the day and appearance changes between different seasons are the major difficulties about this problem, especially when the comparison is made between day‐time and night‐time images for the same scene. This study presents a new extended local difference binary (ELDB) image descriptor that represents a robust appearance invariant extension for the state‐of‐the‐art local difference binary (LDB) image descriptor. This study also introduces a new algorithm for vehicle visual localisation under extreme environmental changes. The new algorithm uses ELDB for image matching, and uses a modified multi‐hypothesis version of the Markov localisation (MHML) filter for self‐localisation. Experimental results show that the proposed modified MHML has reduced computational cost and has resulted in a faster cycle rate. Furthermore, these results show that ELDB has an improved image matching accuracy and requires less processing time compared to the original LDB. The proposed vision‐based vehicle localisation algorithm is shown to be faster and more accurate than other state‐of‐the‐art algorithms

Computational fragment-based drug design of potential Glo-I inhibitors

AbstractIn this study, a fragment-based drug design approach, particularly de novo drug design, was implemented utilising three different crystal structures in order to discover new privileged scaffolds against glyoxalase-I enzyme as anticancer agents. The fragments were evoluted to indicate potential inhibitors with high receptor affinities. The resulting compounds were served as a benchmark for choosing similar compounds from the ASINEX® database by applying different computational ligand-based drug design techniques. Afterwards, the selection of potential hits was further aided by various structure-based approaches. Then, 14 compounds were purchased, and tested in vitro against Glo-I enzyme. Of the tested 14 hits, the biological screening results showed humble activities where the percentage of Glo-I inhibition ranged from 0–18.70 %. Compound 19 and compound 28, whose percentage of inhibitions are 18.70 and 15.80%, respectively, can be considered as hits that need further optimisation in order to be converted into lead-like compounds