Discriminant analysis for the prediction and classification of tick-borne infections in some dairy cattle herds at Dakahlia Governorate, Egypt

This study was undertaken to use the variable loadings in linear discriminant analysis (LDA) to determine the most important predictors for the discrimination of tick-borne diseases (TBDs), particularly babesiosis and anaplasmosis and predict the group membership from the predictors. In total, 163 cattle, from different localities at Dakahlia Governorate, Egypt, were investigated in 2012 and 2013 for the presence of TBDs. All cattle were clinically examined and a clinical index score was determined for each cow. Blood samples were also collected from each animal for adopting microscopy and diagnostic laboratory methods. Out of the examined cattle, 83 animals were acutely-ill (Babesia bovis and Anaplasma marginale were identified in 11 and 10 animals, respectively), while 80 cows were apparently healthy but having previous attacks of blood parasites (23 animals harbored anaplasma marginale (asymptomatic carriers)). The remained 119 animals were negative to TBDs. Fourteen animals were not survived and 149 cases were survived. As the result of the first LDA to discriminate babesiosis, anaplasmosis and negative to TBDs, 89.0% of animals were correctly classified; 78.8% (26/33) for anaplasma, 100% (11/11) for babesia infections, 90.8% (108/119) for negative to TBDs, respectively. The important predictors for the discrimination were oculonasal discharge, bloody feces, hemoglobinuria, bloody feces and respiratory rate. On the other hand, the second LDA discrimination showed high classification accuracy of 87.1% for the discrimination of survivors and non-survivors; 89.9% (134/149) for survivors and 57.1% (8/14) for non-survivors, while the important predictors included oculonasal discharge, recumbent posture and nervous sign

Antibacterial, cytotoxic and trypanocidal activities of marine-derived fungi isolated from Philippine macroalgae and seagrasses

The occurrence and bioactivities of marine-derived fungi are evaluated in this paper. A total of 16 morphospecies of marine-derived fungi (MDF) were isolated from four host macroalgae and two seagrasses and identified as belonging to the genera Aspergillus, Fusarium, Paecilomyces, Penicillium, Sclerotinia, Thamnidium and Trichoderma, including five mycelia sterilia. Among these host organisms, the rhodophyte Laurencia intermedia harboured the highest number of isolated MDF. Selected MDF were then assayed and showed to inhibit Pseudomonas aeruginosa (8-19 mm zone of inhibition) and Staphylococcus aureus (6-19 mm zone of inhibition), and were cytotoxic against the brine shrimp Artemia salina nauplii (LD50: 201.56-948.37 μg mL-1). The screening led to the selection of five of the most bioactive morphospecies, all belonging to the genus Aspergillus. These marine aspergilli were subjected to β-tubulin gene sequence analysis for species identification, and to mass production in different culture media with or without marine salts, and screening of the crude culture extracts for their cytotoxic and trypanocidal activities. Aspergillus tubingensis cultivated in potato dextrose broth with marine salt proved to be the most cytotoxic against P388 (IC50: 1028 ng mL-1) and HeLa (IC50: 1301 ng mL-1) cancer cells. On the other hand, A. fumigatus cultivated in malt extract broth without marine salt was shown to be the most potent against Trypanosoma congolense (IC50: 298.18 ng mL-1). Our study therefore showed that salinity may influence the bioactivities of some species of MDF

Characterization of an epimastigote-stage-specific hemoglobin receptor of Trypanosoma congolense

Background: Since Trypanosorna spp. lack a complete heme synthesis pathway, the parasites are totally dependent on their host for heme throughout all of the stages of their life -cycle. We herein report the identification and characterization of a T. congolense epimastigote form (EMF)-specific hemoglobin (Hb) receptor. The gene was initially reported to encode a T. congolense haptoglobin (Hp)-Hb complex receptor (TcHpHbR) based on its similarity to a gene encoding a T brucei Hp-Hb complex receptor (TbHpHbR). Methods: Trypanosorna congolense IL3000 was used in this study. A TcHpHbR gene was PCR amplified from the parasite genome. The recombinant protein was used as an immunogen to raise antibodies for immunofluorescence assay and immunoblotting. Hemoglobin uptake by the parasite was examined by using Alexa 488 labelled Hb and visualized by confocal laser scanning microscopy. The qualitative and quantitative interaction between TcHpHbR and its ligand were measured using a surface plasmon resonance assay. Results: We found that, unlike TbHpHbR, TcHpHbR was exclusively expressed in the EMF stage at RNA and protein levels. The recombinant TcHpHbR (rTcHpHbR) was co-precipitated with free-Hb in a GST-pull down assay. Surface plasmon resonance revealed that rTcHpHbR binds free-Hb with high affinity (dissociation constant (K,A) =2.1x10(-8) M) but free-Hp with low affinity (Kd = 2.2x10(-7) M). Furthermore, Alexa 488-labelled-Hb was only taken up by the EMF and co-localized with tomato lectin, which is a marker of endocytic compartments (flagellar pocket and lysosome). Conclusion: We conclude that the T. congolense EMF takes up free-Hb via TcHpHbR, a receptor which is specific to this developmental stage. We therefore propose renaming TcHpHbR as T congolense EMF-specific Hb receptor (TcEpHbR)

Effect of a helium gas atmosphere on the mechanical properties of Ti-6Al-4V alloy built with laser powder bed fusion: A comparative study with argon gas

In metal additive manufacturing, the microstructures and associated mechanical properties of metal specimens can be controlled over a wide range. Although process parameters are considered important in the fabrication of functional parts, the effect of atmospheric gas has not been comprehensively documented. In laser powder bed fusion (LPBF), gas flow is used to eliminate fumes generated by laser irradiation. Simultaneously, the gas removes heat from the laser-irradiated part, which is exposed to high temperature. In this study, we investigated the capacity of helium as an alternative to argon, which is conventionally used as the LPBF atmosphere gas. He has a higher thermal conductivity and lower gas density than Ar, which may result in enhanced heat removal from the Ti-6Al-4V alloy during fabrication. Numerical simulations suggest a greater cooling rate under He flow. Further, the material built under He flow contained finer α' martensite grains and showed improved mechanical properties compared to those fabricated under Ar flow, despite the identical laser irradiation conditions. Thus, He gas is advantageous in LPBF for fabricating products with superior mechanical performance through microstructural refinement, and this is a result of its capacity for cooling and fume generation inhibition. Therefore, this study reveals the importance of the choice of atmospheric gas because of its effects on the characteristics of metallic specimens fabricated using LPBF.Amano H., Ishimoto T., Suganuma R., et al. Effect of a helium gas atmosphere on the mechanical properties of Ti-6Al-4V alloy built with laser powder bed fusion: A comparative study with argon gas. Additive Manufacturing, 48, 102444. https://doi.org/10.1016/j.addma.2021.102444

Impact of gas flow direction on the crystallographic texture evolution in laser beam powder bed fusion

This study demonstrated that the gas flow direction in the laser beam powder bed fusion (PBF-LB) significantly affects the crystallographic texture evolved in the products. The effect on texture is attributed to the difference in the melt pool depth, which depends on gas flow direction. The melt pool was shallower when the laser scanning and gas flow directions were parallel than when they were perpendicular. This phenomenon should be of particular concern when applying Scan Strategy_XY wherein the laser was scanned with a 90° rotation in each layer, which is often used in PBF-LB. The asymmetry in the melt pool depth generated by laser scanning in the x- and y-directions can lead to unintended variations in the crystallographic texture. The gas phase would interact with a part being manufactured immediately beneath the gas and affect the crystallographic feature of the product.Amano H., Ishimoto T., Hagihara K., et al. Impact of gas flow direction on the crystallographic texture evolution in laser beam powder bed fusion. Virtual and Physical Prototyping 18, e2169172 (2023); https://doi.org/10.1080/17452759.2023.2169172

Dealkylation of alkyl polycyclic aromatic hydrocarbon over silica monolayer solid acid catalyst

Dealkylation of alkylnaphthalene, as a model of alkyl polycyclic aromatic hydrocarbon compounds in heavy oils, proceeded selectively on a silica monolayer solid acid catalyst. The activity was generated by the deposition of silica on alumina with generation of Brønsted acidity. The activity and Brønsted acid amount showed the maximum where the monolayer covered the surface, indicating that the Brønsted acid site generated on the silica monolayer was the active species. The activity and selectivity on the silica monolayer were high compared to other aluminosilicate catalysts, and high activity was observed even after calcination at 973–1173K

Robust Intensity-Based Localization Method for Autonomous Driving on Snow-Wet Road Surface

金沢大学新学術創成研究機構Autonomous vehicles are being developed rapidly in recent years. In advance implementation stages, many particular problems must be solved to bring this technology into the market place. This paper focuses on the problem of driving in snow and wet road surface environments. First, the quality of laser imaging detection and ranging (LIDAR) reflectivity decreases on wet road surfaces. Therefore, an accumulation strategy is designed to increase the density of online LIDAR images. In order to enhance the texture of the accumulated images, principal component analysis is used to understand the geometrical structures and texture patterns in the map images. The LIDAR images are then reconstructed using the leading principal components with respect to the variance distribution accounted by each eigenvector. Second, the appearance of snow lines deforms the expected road context in LIDAR images. Accordingly, the edge profiles of the LIDAR and map images are extracted to encode the lane lines and roadside edges. Edge matching between the two profiles is then calculated to improve localization in the lateral direction. The proposed method has been tested and evaluated using real data that are collected during the winter of 2016-2017 in Suzu and Kanazawa, Japan. The experimental results show that the proposed method increases the robustness of autonomous driving on wet road surfaces, provides a stable performance in laterally localizing the vehicle in the presence of snow lines, and significantly reduces the overall localization error at a speed of 60 km/h. © 2005-2012 IEEE

Plasmodium knowlesi thioredoxin peroxidase 1 binds to nucleic acids and has RNA chaperone activity

Malaria parasites are under oxidative attack throughout their life cycle in human body and mosquito vector. Therefore, Plasmodium antioxidant defenses are crucial for its survival and being considered as interesting target for antimalarial drug design. Plasmodium knowlesi has emerged recently from its simian host to human in Southeast Asia and has been recognized as the fifth Plasmodium species that can cause human malaria. In this study, we cloned and characterized thioredoxin peroxidase 1 from P. knowlesi (PkTPx-1). PkTPx-1 gene was cloned, and recombinant protein was produced by heterologous overexpression in Escherichia coli. The recombinant protein was used for evaluation of enzymatic activity and polyclonal antibody production. Using the recombinant PkTPx-1 protein, its antioxidant activity was confirmed in a mixed-function oxidation assay where PkTPx-1 prevented nicking of DNA by hydroxyl radicals. PkTPx-1 was able to bind to double-strand DNA and RNA and had RNA chaperone activity in a nucleic acid melting assay indicating new function of PkTPx-1 other than antioxidant activity. Using specific polyclonal antibodies, it was indicated that PkTPx-1 is expressed in the cytoplasm of the parasite. Altogether, these results suggest that PkTPx-1 not only protects the parasite from the adverse effects of reactive oxygen species but also has RNA chaperone activity