61 research outputs found

    Interactions between environmental and safety performance in vehicle design

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    One potential interaction between environmental and safety goals in transport is found within the vehicle fleet where fuel economy and safety impose conflicting requirements on vehicle design. Larger and heavier vehicles have a better secondary safety performance during a crash. On the other hand, they are associated with higher levels of fuel consumption and emissions. This issue has generated debate amongst researchers and policy makers when formulating policies to improve the environmental performance of the road transport system. An extensive review of literature reveals that arguments has often been based on either little research evidence, or research that has inadequacies in the applied methodologies. This research investigates the safety consequences of changes in vehicles mass within the vehicle fleet aimed at increasing fleet fuel economy. The partial effects of mass on fuel consumption rate and secondary safety performance were estimated using a cross-sectional analysis of mass within the British passenger car fleet. Estimation results confirmed that fuel consumption increases as mass increases and were different for different fuel and transmission types. It was shown that vehicle mass has both protective and aggressive safety effects where vehicle size only tends to have protective effects; these were estimated using a novel methodology based on a detailed analysis of two-car crashes. The estimated relationships were used to investigate partial safety and environmental effects of changes in mass distribution within the fleet using an introduced incremental approach. Results generally showed that the relationship between fuel economy and safety performance in vehicle design depends on the characteristics of the vehicle fleet, and in particular, mass distribution. It was shown that an informed change in the mass distribution not only imposes no trade-off between the fuel economy and safety goals, but also could lead to a desirable outcome in both aspects

    Physical, chemical and biological quality assessment of aqueduct (Qanat) water for drinking, agriculture and irrigation of urban green spaces

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    BACKGROUND AND OBJECTIVES: The aqueduct is one of the most complex and amazing inventions of human history, created to meet the most vital needs of human society in arid and semiarid regions areas. If aqueducts are properly maintained, reconstructed, and restored, they can be valuable water supply system from ground water resources. The quality of the water in these sources will have a direct impact on the consumer of its consumption, so it seems necessary to check the water quality of these sources.METHODS: This study investigated the state of five aqueducts in Tehran using parameters such as calcium, magnesium, phosphate, sulfate, turbidity, total hardness, nitrate, alkalinity, electrical conductivity, Biochemical Oxygen Demand, Chemical Oxygen Demand, total coliform and fecal coliform. Then the obtained values were compared with the permissible limits of the World Health Organization and the national standard of Iran. The data was analyzed using SPSS26 software and a one-sample t-test.FINDINGS: The results of water quality during a one-year survey period showed that the parameters of alkalinity, electrical conductivity, total dissolved solids, sulfate, and nitrate were below the maximum desirable and permissible standards of the national standard of Iran and the World Health Organization, and therefore will not create any restrictions for drinking and agricultural use. Total hardness, phosphate, turbidity, calcium, magnesium, and chlorine have discrepancies with the national standards of Iran and the World Health Organization and these components must be adjusted for use. According to the one-sample t-test, there was a significant difference between the average and the permissible values of all parameters except magnesium at the 95% confidence level. All aqueducts except the America aqueduct had levels of fecal coliform that were higher than the maximum allowed by the environmental standards therefore, before using the aqueduct, it must be purified to control the environmental standards.. However, the total coliform, Biochemical Oxygen Demand, Chemical Oxygen Demand levels were not a problem. In addition, the water quality of these sources was placed in a group (C3S1) based on the Wilcox diagram.CONCLUSION: The physical and chemical analysis of the studied aqueduct water showed that the water quality is suitable for the irrigation of green spaces and salt-resistant plants. The biological characteristics of the studied aqueduct water also revealed that these sources were polluted by domestic and industrial effluents. This issue will only grow worse with time, as the amount of rainwater decreases and the amount of pollution in the underground water sources increases

    Mycobiota and aflatoxin B1 contamination of rainbow trout (Oncorhinchus mykiss) feed with emphasis to Aspergillus section Flavi

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    In the present study, mycobiota and natural occurrence of aflatoxin B1 (AFB1) in pellet feed and feed ingredients used in a feed manufacturing plant for rainbow trout nutrition was investigated. The samples were cultured on the standard isolation media for 2 weeks at 28 ºC. Identification of fungal isolates was implemented based on the macro- and microscopic morphological criteria. AFB1 was detected using high performance liquid chromatography (HPLC). Based on the results obtained, a total of 109 fungal isolates were identified of which Aspergillus was the prominent genus (57.0%), followed by Penicillium (12.84%), Absidia (11.01%) and Pseudallscheria (10.10%). The most frequent Aspergillus species was A. flavus (60.66%) isolated from all feed ingredients as well as pellet feed. Among 37 A. flavus isolates, 19 (51.35%) were able to produce AFB1 on YES broth in the range of 10.2 to 612.8 µg/g fungal dry weight. HPLC analysis of trout feed showed that pellet feed and all feed ingredients tested except gluten were contaminated with different levels of AFB1 in the range of 1.83 to 67.35 µg/kg. Unacceptable levels of AFB1 were reported for feed including soybean, fish meal and wheat. These results indicate the importance of AF contamination of trout feed in amounts higher than the acceptable level as a risk factor for fish farming production

    Microfilariae of Brugia malayi Inhibit the mTOR Pathway and Induce Autophagy in Human Dendritic Cells

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    Immune modulation is a hallmark of patent filarial infection, including suppression of antigen-presenting cell function and downmodulation of filarial antigen-specific T cell responses. The mammalian target of rapamycin (mTOR) signaling pathway has been implicated in immune regulation, not only by suppressing T cell responses but also by regulating autophagy (through mTOR sensing amino acid availability). Global proteomic analysis (liquid chromatography-tandem mass spectrometry) of microfilaria (mf)-exposed monocyte-derived dendritic cells (DC) indicated that multiple components of the mTOR signaling pathway, including mTOR, eIF4A, and eIF4E, are downregulated by mf, suggesting that mf target this pathway for immune modulation in DC. Utilizing Western blot analysis, we demonstrate that similar to rapamycin (a known mTOR inhibitor), mf downregulate the phosphorylation of mTOR and its regulatory proteins, p70S6K1 and 4E-BP1, a process essential for DC protein synthesis. As active mTOR signaling regulates autophagy, we examined whether mf exposure alters autophagy-associated processes. mf-induced autophagy was reflected in marked upregulation of phosphorylated Beclin 1, known to play an important role in both autophagosome formation and autolysosome fusion, in induction of LC3II, a marker of autophagosome formation, and in induced degradation of p62, a ubiquitin-binding protein that aggregates protein in autophagosomes and is degraded upon autophagy that was reduced significantly by mf exposure and by rapamycin. Together, these results suggest that Brugia malayi mf employ mechanisms of metabolic modulation in DC to influence the regulation of the host immune response by downregulating mTOR signaling, resulting in increased autophagy. Whether this is a result of the parasite-secreted rapamycin homolog is currently under study

    Transcription of toll-like receptors 2, 3, 4 and 9, FoxP3 and Th17 cytokines in a susceptible experimental model of canine Leishmania infantum infection

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    Canine leishmaniosis (CanL) due to Leishmania infantum is a chronic zoonotic systemic disease resulting from complex interactions between protozoa and the canine immune system. Toll-like receptors (TLRs) are essential components of the innate immune system and facilitate the early detection of many infections. However, the role of TLRs in CanL remains unknown and information describing TLR transcription during infection is extremely scarce. The aim of this research project was to investigate the impact of L. infantum infection on canine TLR transcription using a susceptible model. The objectives of this study were to evaluate transcription of TLRs 2, 3, 4 and 9 by means of quantitative reverse transcription polymerase chain reaction (qRT-PCR) in skin, spleen, lymph node and liver in the presence or absence of experimental L. infantum infection in Beagle dogs. These findings were compared with clinical and serological data, parasite densities in infected tissues and transcription of IL-17, IL-22 and FoxP3 in different tissues in non-infected dogs (n = 10), and at six months (n = 24) and 15 months (n = 7) post infection. Results revealed significant down regulation of transcription with disease progression in lymph node samples for TLR3, TLR4, TLR9, IL-17, IL-22 and FoxP3. In spleen samples, significant down regulation of transcription was seen in TLR4 and IL-22 when both infected groups were compared with controls. In liver samples, down regulation of transcription was evident with disease progression for IL-22. In the skin, upregulation was seen only for TLR9 and FoxP3 in the early stages of infection. Subtle changes or down regulation in TLR transcription, Th17 cytokines and FoxP3 are indicative of the silent establishment of infection that Leishmania is renowned for. These observations provide new insights about TLR transcription, Th17 cytokines and Foxp3 in the liver, spleen, lymph node and skin in CanL and highlight possible markers of disease susceptibility in this model

    Possibilities and challenges for developing a successful vaccine for leishmaniasis

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    Effect Of Quenching Media, Specimen Size And Shape On The Hardenability Of AISI 4140 Steel

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    The purpose of this study is to investigate the influence of different quenching media, size and shape of the specimen on the hardened depth of AISI 4140 steel. The paper demonstrates how these parameters can affect the hardness from the surface to the core of the samples. This study represents the relationship between hardened depth and geometry. Findings reveal the fact that high hardening effect was obtained in water-quenched samples by the virtue of the martensitic structure and lower hardened depth achieved in the air-quenched samples. Significant improvement achieved by increasing the velocity of air when quenched by compressed air. It was also concluded that the hardness of the quenched samples at certain depths can be estimated on the basis of heat transfer equations

    SINTERING EFFECTS ON THE DENSIFICATION OF NANOCRYSTALLINE HYDROXYAPATITE

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    The effects of sintering profiles on the densification behaviour of synthesized nanocrystalline hydroxyapatite (HA) powder were investigated in terms of phase stability and mechanical properties. A wet chemical precipitation method was successfully employed to synthesize a high purity and single phase HA powder. Green HA compacts were prepared and subjected to sintering in air atmosphere over a temperature range of 700° C to 1300° C. In this study two different holding times were compared, i.e. 1 minute versus the standard 120 minutes. The results revealed that the 1 minute holding time sintering profile was indeed effective in producing a HA body with high density of 98% theoretical when sintered at 1200° C. High mechanical properties such as fracture toughness of 1.41 MPa.m1/2 and hardness of 9.5 GPa were also measured for HA samples sintered under this profile. Additionally, XRD analysis indicated that decomposition of the HA phase during sintering at high temperatures was suppressed
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