The depletion of fossil fuels as a result of excessive use and increased environmental pollution brought up the research of environmentally conscious and renewable alternative fuels. The alternative ...fuel to be considered for internal combustion engines should not decrease the performance of the engine too much and positively affect the exhaust emissions. It is also important that this fuel should provide some specifications such as easy producibility, low cost, availability and usability in internal combustion engine without modification. Low temperature combustion modes are promising technologies providing nearly zero NOx and soot emissions and currently a lot of researcher has focused on this technology. In this experimental study naphtha was tested in an HCCI engine. In order to examine and understand the effects of the naphtha on HCCI mode a comparison study was also conducted by using RON68. Maximum imep was computed as 3.23 and 3.32 bar with RON68 and naphtha respectively at λ=1.7. SOC was determined 5.4 °CA and 5.76 °CA ATDC with naphtha and RON68 at λ=2. CA50 is far away from TDC fact that net work decreases. Maximum ITE was calculated as 45.42% and 46.07% at λ=2 with RON68 and naphtha respectively.
Summary
The host range of phages is a key to understand their impact on bacterial ecology and evolution. Because of the complexity of phage–host interactions, the variables that determine the breadth ...of a phage host range remain poorly understood. Here, we propose a novel holistic approach to identify the host range determinants of a new collection of phages infecting Salmonella, isolated from animal, environmental and wastewater samples that were able to infect 58 of the 71 Salmonella strains in our collection. By using a set of statistic approaches (non‐metric dimensional scaling, Bray–Curtis distance, PERMANOVA), we analysed phenotypic (host range on wild‐type and receptor mutants) and genetic data (taxonomic assignment and receptor binding proteins) to evaluate the impact of isolation strain and niche, phage receptor and genus on the host range. Statistical analysis revealed that two phage characteristics influence the host range by explaining the most variance: the receptor by 45% and the genus by 51%. Interestingly, phage genus and receptor in combination explained 79% of the variance, establishing these characteristics as the major determinants of the host range. This study demonstrates the power and the novelty of applying statistical approaches to phenotypic and genetic data to investigate the ecology of phage–host interactions.
•Presence of E. coli O157/O157:H7 in sheep feces and carcasses was investigated.•E. coli O157 was detected from 18% of sheep brought to slaughter over a year.•Effect of categories such as season or ...sex and age range on prevalence was evaluated.•Two and 8% of the sheep feces and carcasses, respectively, harbored STEC O157:H7.•E. coli O157/O157:H7 observed more prevalent in male and yearling sheep.
Escherichia coli O157:H7 is a globally important foodborne pathogen and has been mainly associated with cattle as the reservoir. However, accumulating data shows the importance of sheep as an E. coli O157:H7 vehicle. The presence of E. coli O157/O157:H7 in recto-anal mucosal swap and carcass sponge samples of 100 sheep brought to the slaughterhouse in Kirikkale were analyzed over a year. Molecular characteristics (stx1, stx2, eaeA, hly, lpfA1-3, espA, eae-α1, eae-α2, eae-β, eae-β1, eae-β2, eae-γ1, eae-γ2/θ, stx1c, stx1d, stx2c, stx2d, stx2e, stx2f, stx2g, blaampC, tet(A), tet(B), tet(C), tet(D), tet(E), tet(G), sul1, sul2, floR, cmlA, strA, strB and aadA) of 79 isolates were determined and minimum inhibitory concentrations of 20 different antibiotics were investigated. E. coli O157/O157:H7 was found in 18% of sheep included in the study and was more prevalent in yearlings than lambs and mature sheep, and male than female sheep, though none of the categories (season, sex or age range) had significant effect on prevalence. Furthermore, Shiga-toxigenic E. coli (STEC) O157:H7 was determined in 2% and 8% of sheep feces and carcasses, respectively. Additionally, lpfA1-3 and eae-γ1 were detected in all isolates. None of the isolates showed resistance against investigated antibiotics, even though 4 sorbitol fermenting E. coli O157 isolates were positive for tet(A), sul1 and aadA. This is the first study in Turkey that reveals the potential public health risk due to the contamination of sheep carcasses with potentially highly pathogenic STEC O157:H7 strains.
Background and Objectives: In addition to left ventricular (LV) functions, right ventricular (RV) functions and pulmonary arterial stiffness (PAS) may be adversely affected in patients with heart ...failure with reduced ejection fraction (HFrEF). Sodium-glucose co-transporter-2 (SGLT2) inhibitor therapy positively affects LV functions as well as having functional and symptomatic benefits in HFrEF patients. In this study, we aimed to evaluate the effects of SGLT2 inhibitor treatment on RV function and PAS in HFrEF patients. Materials andMethods: 168 HFrEF patients with New York Heart Association (NYHA) class ≥2 symptoms despite optimal medical treatment and who were started on SGLT2 inhibitor therapy were included in this retrospective study. NYHA classification, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, Minnesota Living with Heart Failure Questionnaire (MLWHFQ) scores, laboratory tests, and transthoracic echocardiography (TTE) measurements were recorded before treatment and at the end of the 6-month follow-up. Results: The mean age of the patients was 62.7 ± 11.4 years, and 38 (22.6%) were women. RV function (RV fractional area change (FAC) (33.8 ± 6.4% vs. 39.2 ± 7.3%, p < 0.001); tricuspid annular plane systolic excursion (TAPSE) (18.4 ± 3.8 mm vs. 19.6 ± 3.6 mm, p < 0.001); RV S’ (10 (8 − 13) cm/s vs. 13 (10 − 16) cm/s, p < 0.001); RV myocardial performance index (RV MPI) (0.68 ± 0.12 vs. 0.59 ± 0.11, p < 0.001); mean pulmonary artery pressure (mPAP) (39.6 ± 7.8 mmHg vs. 32 ± 6.8 mmHg, p = 0.003)) and PAS (24.2 ± 4.6 kHz/ms vs. 18.6 ± 3.1 kHz/ms, p < 0.001) values at the 6-month follow-up after SGLT2 inhibitor therapy significantly improved. It was found that SGLT2 inhibitor treatment provided significant improvement in NYHA classification, MLWHFQ scores, and NT-proBNP levels (2876 ± 401 vs. 1034 ± 361, p < 0.001), and these functional and symptomatic positive changes in HFrEF patients were significantly correlated with positive changes in LVEF, PAS, and RV functional status. Conclusions: SGLT2 inhibitor treatment results in symptomatic and functional well-being in HFrEF patients, as well as positive changes in RV function and PAS.
Bu çalışmanın amacı Amerikan Dow Jones indeksi emtia piyasasında yer alan Emtia Fiyatları kullanılarak, Amerikan emtia piyasasında spekülatif balonlarının var olup olmadığı, varsa toplam balon ...süreleri ve incelenen dönemde kaç kez spekülatif balon oluştuğunun belirlenmesidir. Çalışmada Amerikan Dow Jones indeksi emtia piyasasında yer alan 23 adet gerçek zamanlı Emtia fiyatları kullanılmış, 01.01.2012 tarihinden 01.08.2022 tarihine kadar 10 yıllık dönemde, aylık veriler üzerinden Phillips, Shi ve Yu (2015) tarafından literatüre kazandırılan genelleştirilmiş Dickey Fuller (GSADF) testi kullanılmıştır. Çalışma sonucunda incelenen zaman aralığında ve emtiaların tamamında fiyat balonu veya balonlarının çeşitli defa ve sürelerde oluştuğu belirlenmiştir. Emtia piyasasında bir balonun varlığı ulusal ve uluslararası ekonomi üzerinde yıkıcı etkiler yaratabilir. GSADF testlerinin gerçek zamanlı bir kabarcık detektörü olarak kullanılabileceği göz önüne alındığında bu yaklaşımın uygulanması ve politika yapıcılar tarafından yapılan zamanla değişen nedensellik testleri, dışsal veya dış kaynaklı risklerin değerlendirilmesi ve ölçülmesi açısından önemli faydalar sağlayabilir.
The aim of this study is to determine whether there are speculative bubbles in the American commodity market, if so, their duration and how many speculative bubbles occur in the analyzed period by using the commodity prices in the American Dow Jones index commodity market. In the study, 23 real-time commodity prices in the American Dow Jones index commodity market were used and the generalized Dickey Fuller (GSADF) test, which was brought to the literature by Phillips, Shi, and Yu (2015) over the monthly data in a 10-year period from 01.01.2012 to 01.08.2022. used. As a result of the study, it was determined that price bubble or bubbles occurred in various times and periods in the examined time period and in all of the commodities. The existence of a bubble in the commodity market can have devastating effects on the national and international economy. Considering that GSADF tests can be used as a real-time bubble detector, the application of this approach and time-varying causality tests by policy makers can provide significant benefits for the assessment and measurement of exogenous or exogenous risks.
Bacteriophages recognize their host cells with the help of tail fiber and tailspike proteins that bind, cleave, or modify certain structures on the cell surface. The spectrum of ligands to which the ...tail fibers and tailspikes can bind is the primary determinant of the host range. Bacteriophages with multiple tailspike/tail fibers are thought to have a wider host range than their less endowed relatives but the function of these proteins remains poorly understood. Here, we describe the structure, function, and substrate specificity of three tailspike proteins of bacteriophage CBA120—TSP2, TSP3 and TSP4 (orf211 through orf213, respectively). We show that tailspikes TSP2, TSP3 and TSP4 are hydrolases that digest the O157, O77, and O78 Escherichia coli O-antigens, respectively. We demonstrate that recognition of the E. coli O157:H7 host by CBA120 involves binding to and digesting the O157 O-antigen by TSP2. We report the crystal structure of TSP2 in complex with a repeating unit of the O157 O-antigen. We demonstrate that according to the specificity of its tailspikes TSP2, TSP3, and TSP4, CBA120 can infect E. coli O157, O77, and O78, respectively. We also show that CBA120 infects Salmonella enterica serovar Minnesota, and this host range expansion is likely due to the function of TSP1. Finally, we describe the assembly pathway and the architecture of the TSP1–TSP2–TSP3–TSP4 branched complex in CBA120 and its related ViI-like phages.
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Amaç: Çalışmanın amacı, şirketlerin değer yaratma esasına dayalı önemli finansal performans göstergeleri olan Serbest Nakit Akımı (FCF), Firma Değeri (EV), Firma Değeri/Faiz, Vergi ve Amortisman ...Öncesi Kar (EV/EBITDA) ve Fiyat/Kazanç (P/E) aralarındaki ilişkilerin belirlenmesi ve yorumlanmasıdır.Yöntem: Çalışmada BİST 30 şirketlerinin 2015-2021 yıllarında FCF ile EV, P/E ve EV/EBITDA yıllık değerleri arasındaki ilişki panel veri analiz yöntemi ile incelenmiştir.Bulgular: Yapılan analizler sonucunda FCF ile EV ve P/E aralarında aynı yönlü; FCF ile EV/EBITDA arasında ters yönlü ilişki olduğu belirlenmiştir. Elde edilen bulguların literatürdeki çalışmalarla kısmen uyumlu olduğu belirlenmiştir.Özgünlük: Çalışmanın BIST-30 endeksindeki kapsamındaki şirketler için değer maksimizasyonunu esas alan şirket performans ölçüm göstergeleri belirlenerek bu göstergeler arasındaki ilişkiler ortaya konulması ve yorumlanması açısından özgün olduğu değerlendirilmektedir. Daha önce literatürde incelenen örneklem ve zaman aralığında herhangi bir çalışma bulunmamaktadır.
Purpose: The aim of the study is to determine and to interpret the relationship between Free Cash Flow (FCF), Firm Value (EV), Firm Value/Earnings Before Interest, Taxes and Depreciation (EV/EBITDA) and Price/Earnings (P/E) which are important financial performance indicators of companies based on value creation.Methodology: In the study, the relationship between the annual values of FCF and EV, P/E and EV/EBITDA of BIST 30 companies was examined by panel data analysis method in the years 2015-2021.Findings: As a result of the analysis; it has been determined that EV and P/E are in the same direction with FCF and there is an inverse relationship between FCF and EV/EBITDA. It was determined that the findings are partially consistent with the studies in the literature.Originality: The study is original in terms of revealing and interpreting the relationships between performance measurement indicators based on value maximization for the companies within the scope of the BIST-30 index. There is no study using same sample and time period previously in the literature.
The prevalence and seasonal distribution of E. coli O157:H7+/H7– in an array of aged cattle at slaughter and its dissemination with slaughterhouse wastewater over a two year period in Turkey were ...investigated. For this purpose, a total of 720 samples (240 rectoanal mucosal swap RAMS, 240 carcass sponge and 240 bile samples) of 240 cattle categorized according to age, gender, breed and sampling site were collected along with additional 24 wastewater samples and were subjected to immunomagnetic separation based cultivation technique to efficiently isolate E. coli O157 from the background flora. Identification (rfbEO157, fliCh7), detection of major virulence factors (stx1, stx2, eaeA, hly, lpfA1-3 and espA), intimin variants (eae-α1, eae-α2, eae-β, eae-β1, eae-β2, eae-γ1 and eae-γ2/θ) and shiga toxin variants (stx1c, stx1d, stx2c, stx2d, stx2e, stx2f and stx2g) of all the isolates were assessed by PCR. From 10 (4.2%) of RAMS and 11 (4.6%) of carcass sponge samples and 5 (20.8%) of slaughterhouse wastewater samples, a total of 102 colonies (99 sorbitol negative and 3 sorbitol positive) were isolated. Overall, 17 (7.1%) and 15 (6.3%) of 240 sampled cattle were shown to harbor E. coli O157 and E. coli O157:H7, respectively either in their RAMS or carcass sponge samples analyzed. Statistically significant differences between categories; season, age, gender and breed of cattle were not observed (p>0.05). None of the isolated E. coli O157:H7+/H7– strains harbored any of the investigated intimin types other than eaeγ1 or shiga toxin variants stx1d, stx2e, stx2f or stx2g while all were lpfA1-3+ except 5 E. coli O157:H7– strains. Intimin variant eaeγ1 and shiga toxin 1 variant stx1c were detected from all of the eaeA+ (97/102, 95.1%) and stx1+ (32/102, 31.3%) strains, respectively while from stx2+ (80/102, 78.4%) isolates, both stx2c (68/80, 85.0%) and stx2d (12/80, 15.0%) variants were determined. In the last decade, prevalence of E. coli O157:H7 has an increasing trend in cattle. Slaughterhouses are the significant sources of environmental contamination with E. coli O157:H7. Isolation and molecular characterization of sorbitol fermenting E. coli O157:H7 are a novel finding and may lead to a revision of reference isolation procedure of E. coli O157:H7 in future.
•E. coli O157:H7 was examined in cattle and slaughterhouse wastewater samples.•Effect of season, age, gender and breed on prevalence was determined.•Major virulence genes and gene variants were assessed by PCR.•Sorbitol fermenting E. coli O157:H7 was isolated and characterized.•Wastewater is a significant source of E. coli O157:H7 environmental contamination.
•Dynamical characterisation of novel 3D axisymmetric chiral auxetic structure showed a nominal stress–strain relationship typical for cellular materials, which was strongly strain-rate dependant.•The ...structure exhibited a pronounced negative Poisson ratio, proving it's auxetic response.•The Poisson's ratio in all structures gradually increased during deformation, making them superior to traditional cellular materials with a sudden increase in Poisson's ratio.•The modification of conventional Split Hopkinson Pressure bar to Direct impact Hopkinson bar, enables the dynamic characterisation of cellular material.
The study presents an extensive mechanical and computational characterisation of novel cellular metamaterial with axisymmetric chiral structure (ACS) at different strain rates. The Direct Impact Hopkinson Bar (DIHB) testing device was used for impact testing up to 21 m/s striker speed, which was insufficient to reach the shock deformation regime. Thus, using computational simulations to estimate the structure behaviour at high strain rates was necessary. Experimental and computational results showed that all ACS structures exhibit a nominal stress–strain relationship typical for cellular materials. As the loading conditions shifted to a dynamic regime, the micro–inertia effect became increasingly pronounced, leading to a corresponding rise in structure stiffness. The Poisson's ratio in all ACS increases gradually, making them superior to traditional cellular materials, which experience a sudden increase in Poisson's ratio during loading. Additionally, the study found that the structures exhibited a rise in the auxetic effect with an increase in strain rate, highlighting the benefits of axisymmetric structures in high-loading regimes. Overall, the obtained results provide valuable insights into the mechanical properties of ACS under different loading regimes and will contribute to further design improvements and the fabrication of novel ACS metamaterials.
Bacterial defense against phage predation involves diverse defense systems acting individually and concurrently, yet their interactions remain poorly understood. We investigated >100 defense systems ...in 42,925 bacterial genomes and identified numerous instances of their non-random co-occurrence and negative association. For several pairs of defense systems significantly co-occurring in Escherichia coli strains, we demonstrate synergistic anti-phage activity. Notably, Zorya II synergizes with Druantia III and ietAS defense systems, while tmn exhibits synergy with co-occurring systems Gabija, Septu I, and PrrC. For Gabija, tmn co-opts the sensory switch ATPase domain, enhancing anti-phage activity. Some defense system pairs that are negatively associated in E. coli show synergy and significantly co-occur in other taxa, demonstrating that bacterial immune repertoires are largely shaped by selection for resistance against host-specific phages rather than negative epistasis. Collectively, these findings demonstrate compatibility and synergy between defense systems, allowing bacteria to adopt flexible strategies for phage defense.
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•Co-occurring bacterial defense systems display synergistic anti-phage activity•Zorya II synergizes with Druantia III and ietAS, and tmn synergizes with Gabija and Septu I•Tmn synergizes with defense systems containing sensory switch ATPase domains•Active systems recruit functional domains of inactive systems for enhanced efficacy
Bacteria defend against phages using a variety of defense systems, yet their interactions are poorly understood. Wu and Garushyants et al. reveal that these defense systems are generally compatible and, in some instances, interact resulting in synergistic anti-phage effects, conferring an evolutionary advantage on bacteria under specific environmental conditions.
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