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Impact assessment of the Internet of Things on feeder transit performance
No full textEfficient planning for demand responsive transit (DRT) can contribute to fulfilling the first/last mile transport needs for users of a major transit line. With the advancement in communication technologies, the internet is expected to assist this growing need of providing first/last mile connectivity. This is proposed to be achieved through a network created by Internet of Things (IoT). This paper evaluates the effect of implementation of IoT on service quality (or disutility) of DRT for two scenarios - with enabled-IoT (e-IoT) and with disabled-IoT (d-IoT). Data from five different DRT-like systems known as Call-n-Ride (CnR) routes operating in Denver, Colorado, are used for evaluation purposes. These CnR routes are Meridian, Interlocken, South Inverness, Broomfield and Louisville. Results show that, in general, all CnR routes would experience more than a 58 percent decrease in disutility if their operations were based on `with e-IoT' operations. Interlocken would record the largest percentage decrease (74 percent) in disutility if its route service switched from the `with d-IoT' to the `with e-IoT' scenario
Does shortwave absorption by methane influence its effectiveness?
No full textIn this study, using idealized step-forcing simulations, we examine the effective radiative forcing of CH4 relative to that of CO2 and compare the effects of CH4 and CO2 forcing on the climate system. A tenfold increase in CH4 concentration in the NCAR CAM5 climate model produces similar long term global mean surface warming (similar to 1.7 K) as a one-third increase in CO2 concentration. However, the radiative forcing estimated for CO2 using the prescribed-SST method is similar to 81% that of CH4, indicating that the efficacy of CH4 forcing is similar to 0.81. This estimate is nearly unchanged when the CO2 physiological effect is included in our simulations. Further, for the same long-term global mean surface warming, we simulate a smaller precipitation increase in the CH4 case compared to the CO2 case. This is because of the fast adjustment processesprecipitation reduction in the CH4 case is larger than that of the CO2 case. This is associated with a relatively more stable atmosphere and larger atmospheric radiative forcing in the CH4 case which occurs because of near-infrared absorption by CH4 in the upper troposphere and lower stratosphere. Within a month after an increase in CH4, this shortwave heating results in a temperature increase of similar to 0.8 K in the lower stratosphere and upper troposphere. In contrast, within a month after a CO2 increase, longwave cooling results in a temperature decrease of similar to 3 K in the stratosphere and a small change in the upper troposphere. These fast adjustments in the lower stratospheric and upper tropospheric temperature, along with the adjustments in clouds in the troposphere, influence the effective radiative forcing and the fast precipitation response. These differences in fast climate adjustments also produce differences in the climate states from which the slow response begins to evolve and hence they are likely associated with differing feedbacks. We also find that the tropics and subtropics are relatively warmer in the CH4 case for the same global mean surface warming because of a larger longwave clear-sky and shortwave cloud forcing over these regions in the CH4 case. Further investigation using a multi-model intercomparison framework would permit an assessment of the robustness of our results
Evaluating the impact of Idea-Inspire 4.0 on analogical transfer of concepts
No full textThe biological domain has the potential to offer a rich source of analogies to solve engineering design problems. However, due to the complexity embedded in biological systems, adding to the lack of structured, detailed, and searchable knowledge bases, engineering designers find it hard to access the knowledge in the biological domain, which therefore poses challenges in understanding the biological concepts in order to apply these concepts to engineering design problems. In order to assist the engineering designers in problem-solving, we report, in this paper, a web-based tool called Idea-Inspire 4.0 that supports analogical design using two broad features. First, the tool provides access to a number of biological systems using a searchable knowledge base. Second, it explains each one of these biological systems using a multi-modal representation: that is, using function decomposition model, text, function model, image, video, and audio. In this paper, we report two experiments that test how well the multi-modal representation in Idea-Inspire 4.0 supports understanding and application of biological concepts in engineering design problems. In one experiment, we use Bloom's method to test ``analysis'' and ``synthesis'' levels of understanding of a biological system. In the next experiment, we provide an engineering design problem along with a biological-analogous system and examine the novelty and requirement-satisfaction (two major indicators of creativity) of resulting design solutions. In both the experiments, the biological system (analogue) was provided using Idea-Inspire 4.0 as well as using a conventional text-image representation so that the efficacy of Idea-Inspire 4.0 is tested using a benchmark
Inflammatory Role of Cancer-Associated Fibroblasts in Invasive Breast Tumors Revealed Using a Fibrous Polymer Scaffold
No full textInflammation in cancer fuels metastasis and worsens prognosis. Cancer-associated fibroblasts (CAFs) present in the tumor stroma play a vital role in mediating the cascade of cancer inflammation that drives metastasis by enhancing angiogenesis, tissue remodeling, and invasion. In vitro models that faithfully recapitulate CAF-mediated inflammation independent of coculturing with cancer cells are nonexistent. We have engineered fibrous matrices of poly(epsilon-caprolactone) (PCL) that can maintain the manifold tumor-promoting properties of patient-derived CAFs, which would otherwise require repetitive isolation and complex coculturing with cancer cells. On these fibrous matrices, CAFs proliferated and remodeled the extracellular matrix (ECM) in a parallel-patterned manner mimicking the ECM of high-grade breast tumors and induced sternness in breast cancer cells. The response of the fibroblasts was observed to be sensitive to the scaffold architecture and not the polymer composition. The CAFs cultured on fibrous matrices exhibited increased activation of the NF-kappa B pathway and downstream proinflammatory gene expression compared to CAFs cultured on conventional two-dimensional (2D) dishes and secreted higher levels of proinflammatory cytokines such as IL-6, GM-CSF, and MIP-3 alpha. Consistent with this, we observed increased infiltration of inflammatory cells to the tumor site and enhanced invasiveness of the tumor in vivo when tumor cells were injected admixed with CAFs grown on fibrous matrices. These data suggest that CAFs better retain their tumor-promoting proinflammatory properties on fibrous polymeric matrices, which could serve as a unique model to investigate the mechanisms of stroma-induced inflammation in cancer progression
Cage Encapsulated Gold Nanoparticles as Heterogeneous Photocatalyst for Facile and Selective Reduction of Nitroarenes to Azo Compounds
No full textA discrete nanoscopic organic cage (OC1(R)) has been synthesized from a phenothiazine based trialdehyde treating with chiral 1,2-cyclohexanediamine building block via dynamic imine bond formation followed by reductive amination. The cage compound has been characterized by several spectroscopic methods, which advocate that OC1(R) has trigonal prismatic shape formed via 2 + 3] self-assembled imine condensation followed by imine reduction. This newly designed cage has aromatic walls and porous interior decorated with two cyclic thioether and three vicinal diamine moieties suitable for binding gold ions to engineer the controlled nucleation and stabilization of ultrafine gold nanoparticles (AuNPs). The functionalized confined pocket of the cage has been used for the controlled synthesis of AuNPs with narrow size distribution via encapsulation of Au(III) ions. Inductively coupled plasma mass spectrometric (ICP-MS) analysis revealed that the composite Au@OC1(R) has very high (similar to 68 wt %) gold loading. In distinction, reduction of gold salts in absence of the cage yielded structureless agglomerates. The fine-dispersed cage anchored AuNPs (Au@OC1(R)) have been finally used as potential heterogeneous photocatalyst for very facile and selective conversion of nitroarenes to respective azo compounds at ambient temperature in just 2 h reaction time. Exceptional chemical stability and reusability without any agglomeration of AuNPs even after several cycles of use are the potential features of this material. The composite Au@OC1(R) represents the first example of organic cage supported gold nanoparticles as photocatalyst
Finite Element Analysis to Probe the Influence of Acetabular Shell Design, Liner Material, and Subject Parameters on Biomechanical Response in Periprosthetic Bone
No full textThe implant stability and biomechanical response of periprosthetic bone in acetabulum around total hip joint replacement (THR) devices depend on a host of parameters, including design of articulating materials, gait cycle and subject parameters. In this study, the impact of shell design (conventional, finned, spiked, and combined design) and liner material on the biomechanical response of periprosthetic bone has been analyzed using finite element (FE) method. Two different liner materials: high density polyethylene-20% hydroxyapatite-20% alumina (HDPE-20%HA-20%Al2O3) and highly cross-linked ultrahigh molecular weight polyethylene (HC-UHMWPE) were used. The subject parameters included bone condition and bodyweight. Physiologically relevant load cases of a gait cycle were considered. The deviation of mechanical condition of the periprosthetic bone due to implantation was least for the finned shell design. No significant deviation was observed at the bone region adjacent to the spikes and the fins. This study recommends the use of the finned design, particularly for weaker bone conditions. For stronger hones, the combined design may also be recommended for higher stability. The use of HC-UHMWPE liner was found to be better for convensional shell design. However, similar biomechanical response was captured in our FE analysis for both the liner materials in case of other shell designs. Overall, the study establishes the biomechanical response of periprosthetic bone in the acetabular with preclinically tested liner materials together with new shell design for different subject conditions
A simple and versatile machine for creep testing at low loads (6-300 N) and on miniaturized specimens: Application to a Mg-base alloy
No full textHigh temperature creep testing at a very lowload range (< 10 N) on miniaturized specimens has always been a challenge due to inherent design limitation (such as significant preload) of the conventional creep testing machines. In the present study, the challenge was overcome by developing a simple and versatile horizontal creep testing machine to conduct creep tests in the loading range of similar to 6-300 N in tension and in compression. The competence of the in-house-built horizontal creep machine was validated by conducting creep testing on dog-bone shaped sheet specimens of cast Mg-1Sn-1Ca (TX11) Mg-base alloy over a lower stress range of 1.6-5.9 MPa (equivalent load range of 6.4-18.1 N) at 450 degrees C and in the high stress range of 20-80 MPa (equivalent load range of 76-310 N) at 175 degrees C. Published by AIP Publishing
High capacity MoO(3/)rGO nanocomposite anode for lithium ion batteries: an intuition into the conversion mechanism of MoO3
No full textMoO3 is a potential anode material for Li-ion batteries (LIBs) because of its high theoretical capacity (1117 mA h g(-1)). The major hurdles in realizing this high capacity are its low conductivity and large volume variations during intercalation/de-intercalation processes. To mitigate these shortcomings, we have synthesized reduced graphene oxide (rGO) wrapped MoO3 nanoparticles (NPs). This involves the synthesis of MoO3 NPs as the first step and then subjecting the synthesized MoO3 NPs to hydrothermal treatment along with graphene oxide (GO) sheets to form rGO wrapped MoO3 NPs. Electrochemical impedance spectra show that a 13% MoO3/rGO nanocomposite has the least conductive resistance among the different nanocomposites. Several physicochemical characterization techniques have been used to confirm the desired state of the obtained material. Ex-XRD studies were carried out to inspect the mechanism of MoO3 and found that it initially follows a simple lithiation/delithiation mechanism and later it adopts a conversion mechanism. The new architecture exhibits an excellent electrochemical performance by displaying a high first specific discharge capacity value (984 mA h g(-1)) and remarkable stability (901 mA h g(-1) even after 100 cycles)
Interaction of miR-125b-5p with Human antigen R mRNA: Mechanism of controlling HCV replication
No full textCellular miRNAs influence Hepatitis C virus (HCV) infection in multiple ways. In this study, we demonstrate that miR-125b-5p is upregulated in HCV infected patient serum samples as well as in HCV infected liver carcinoma cells and is involved in translational regulation of one of its predicted targets, Human antigen R (HuR). We used miRNA mimics and antagomiRs to confirm that HuR is a bonafide miR-125b target. Previously, we have shown that HuR is a positive regulator of HCV replication, whereas we noticed that miR-125b is a negative regulator of HCV infection. As a connecting link between these two observations, we showed that knockdown of miR-125b-5p increased HuR protein levels and rescued HCV replication when the availability of HuR in the cytoplasm was compromised using siRNAs against HuR or an inhibitor of HuR export to the cytoplasm. Overall, the study sheds light on the ability of host cell to use a miRNA as a tool to control virus propagation
Tunable order-disorder continuum in protein-DNA interactions
No full textDNA-binding protein domains (DBDs) sample diverse conformations in equilibrium facilitating the search and recognition of specific sites on DNA over millions of energetically degenerate competing sites. We hypothesize that DBDs have co-evolved to sense and exploit the strong electric potential from the array of negatively charged phosphate groups on DNA. We test our hypothesis by employing the intrinsically disordered DBD of cytidine repressor (CytR) as a model system. CytR displays a graded increase in structure, stability and folding rate on increasing the osmolarity of the solution that mimics the non-specific screening by DNA phosphates. Electrostatic calculations and an Ising-like statistical mechanical model predict that CytR exhibits features of an electric potential sensor modulating its dimensions and landscape in a unique distance-dependent manner, while DNA plays the role of a non-specific macromolecular chaperone. Accordingly, CytR binds its natural half-site faster than the diffusion-controlled limit and even random DNA conforming to an electrostatic-steering binding mechanism. Our work unravels for the first time the synergistic features of a natural electrostatic potential sensor, a novel binding mechanism driven by electrostatic frustration and disorder, and the role of DNA in promoting distance-dependent protein structural transitions critical for switching between specific and non-specific DNA-binding modes