164 research outputs found
Sensitivity analysis on dynamic responses of geometrically imperfect base excited cantilevered beams
The non-linear non-planar dynamic responses of a near-square cantilevered geometrically imperfect (i.e., slightly curved) beam under harmonic primary resonant base excitation with a one-to-one internal resonance is investigated. By assuming two different geometric imperfection shapes, the sensitivity of the perfect beam model predicted limit-cycles to small geometric imperfections is analyzed by continuing them versus the imperfection parameter incorporating the imperfect beam model. This was carried out by assuming that the corresponding frequency detuning parameter associated with each limit-cycle is fixed. Also, other possible branches of dynamic solutions for the corresponding fixed detuning parameter within the interval of the imperfection amplitude are determined and the importance of accounting for the small geometric imperfections is discussed
Utilization of petroleum hydrocarbons by Pseudomonas sp. and transformed E. coli
Our previous studies showed that the biodegradation of petroleum oil by a i>pseudomonas isolated from a petroleum-contaminated soil was instable. In this work, t is shown that when the isolates are immobilized on Perlite, they are more stable for oil egradation. Although the isolate did not have any chemotaxis to octadecane, dodecane and ctane but utilize octadecane and dodecane better than octane and it did not utilized exane, benzene, kerosene, pentane, heptane or thiophenol. The generation time for degradation of petroleum oil, dodecane and octadecane was 20, 22, and 25 h respectively. This phenotype was not transformed to Pseudomonas by conjugation even with lysozyme treatment, however the petroleum oil and octadecane utilization were transformed to E. coli by lysozyme treatment. The transformed E. coli lost the ability to use octadecane after three subcultures on nutrient broth and 34 generations.African Journal of Biotechnology Vol. 4 (2), pp. 172-176, 200
Integrated stochastic life cycle benefit cost analysis of hydronically-heated apron pavement system
Transportation infrastructure is greatly impacted by ice and snow, adding enormous costs to the American economy. Because of their sustainability benefits, heated-pavement systems (HPS) continue to gain attention as a potential alternative to conventional snow removal operations, and the main goal of this paper is to assess the economic feasibility of hydronically-heated pavements systems (HHPS), one type of heated pavements, for use at apron areas of commercial airports. Both benefits and expenses associated with use of HHPS for snow and ice removal were identified and quantified in monetary terms using a stochastic economic analysis method, and a sensitivity analysis approach was used to determine particular variables that significantly influence overall economic viability of HHPS. The findings suggest that, despite high capital costs, HHPS use at airports might be economically feasible. The results from the sensitivity analysis indicate that airport size, in the context of number of aircraft operations, strongly affects the benefit-cost ratio of HHPS use
Human vault-associated non-coding RNAs bind to mitoxantrone, a chemotherapeutic compound
Human vaults are the largest cytoplasmic ribonucleoprotein and are overexpressed in cancer cells. Vaults reportedly function in the extrusion of xenobiotics from the nuclei of resistant cells, but the interactions of xenobiotics with the vault-associated proteins or non-coding RNAs have never been directly observed. In the present study, we show that vault RNAs (vRNAs), specifically the hvg-1 and hvg-2 RNAs, bind to a chemotherapeutic compound, mitoxantrone. Using an in-line probing assay (spontaneous transesterification of RNA linkages), we have identified the mitoxantrone binding region within the vRNAs. In addition, we analyzed the interactions between vRNAs and mitoxantrone in the cellular milieu, using an in vitro translation inhibition assay. Taken together, our results clearly suggest that vRNAs have the ability to bind certain chemotherapeutic compounds and these interactions may play an important role in vault function, by participating in the export of toxic compounds
Immunity, Sex Hormones, and Environmental Factors as Determinants of COVID-19 Disparity in Women
The current coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2), has resulted in a major global pandemic, causing extreme morbidity and mortality. Few studies appear to suggest a significant impact of gender in morbidity and mortality, where men are reported at a higher risk than women. The infectivity, transmissibility, and varying degree of disease manifestation (mild, modest, and severe) in population studies reinforce the importance of a number of genetic and epigenetic factors, in the context of immune response and gender. The present review dwells on several contributing factors such as a stronger innate immune response, estrogen, angiotensin-converting enzyme 2 gene, and microbiota, which impart greater resistance to the SARS-CoV-2 infection and disease progression in women. In addition, the underlying importance of associated microbiota and certain environmental factors in gender-based disparity pertaining to the mortality and morbidity due to COVID-19 in women has also been addressed.Institute for Research and Medical Consultatio
Communication Biophysics
Contains reports on five research projects.National Institutes of Health (Grant 5 RO1 NB-05462-02)National Aeronautics and Space Administration (Grant NsG-496)National Science Foundation (Grant GP-2495)National Institutes of Health (Grant MH-04737-05
Prevalence and impact of comorbid chronic pain and cigarette smoking among people living with HIV
Rates of chronic pain and cigarette smoking are each substantially higher among people living with HIV (PLWH) than in the general population. The goal of these analyses was to examine the prevalence and impact of comorbid chronic pain and cigarette smoking among PLWH. Participants included 3289 PLWH (83% male) who were recruited from five HIV clinics. As expected, the prevalence of smoking was higher among PLWH with chronic pain (41.9%), than PLWH without chronic pain (26.6%, p <.0001), and the prevalence of chronic pain was higher among current smokers (32.9%), than among former (23.6%) or never (17%) smokers (ps <.0001). PLWH who endorsed comorbid chronic pain and smoking (vs. nonsmokers without chronic pain) were more likely to report cocaine/crack and cannabis use, be prescribed long-term opioid therapy, and have virologic failure, even after controlling for relevant sociodemographic and substance-related variables (ps <.05). These results contribute to a growing empirical literature indicating that chronic pain and cigarette smoking frequently co-occur, and extend this work to a large sample of PLWH. Indeed, PLWH may benefit from interventions that are tailored to address bidirectional pain-smoking effects in the context of HIV
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