170 research outputs found
A 3D beam-column element implemented within a hybrid force-based method
This paper describes a force-based beam-column element implemented using a hybrid force-based solution strategy.
The element can accommodate elastic-plastic strain hardening material behaviour under various loadings including
axial, torsion, bending and shear deformation, both in and out of the plane of the element. In order to overcome
difficulties associated with conventional displacement-based and force-based methods a hybrid force based-method is
proposed. This alternative approach is based on simultaneous use of the principles of minimum total potential energy
and minimum complementary potential energy. Here the primary equation is the equilibrium equation rather than the
compatibility equation (the latter takes precedence when following a displacement based solution strategy). The
predictions of the element using this solution procedure are compared against predictions from AbaqusTM
, showing
excellent agreemen
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Flow shear suppression of turbulence using externally driven ion Bernstein and Alfven waves
The utilization of externally-launched radio-frequency waves as a means of active confinement control through the generation of sheared poloidal flows is explored. For low-frequency waves, kinetic Alfven waves are proposed, and are shown to drive sheared E {times} B flows as a result of the radial variation in the electromagnetic Reynolds stress. In the high frequency regime, ion Bernstein waves are considered, and shown to generate sheared poloidal rotation through the pondermotive force. In either case, it is shown that modest amounts of absorbed power ({approximately} few 100 kW) are required to suppress turbulence in a region of several cm radial width
Hyalomma anatolicum as the main infesting tick in an important livestock rearing region, central area of iran
Background: This study was carried out to determine the infestation of domestic ruminants to ticks in an important livestock-rearing region, located in central part of Iran. Methods: Ticks were collected from cattle, sheep, and goats and then were identified with appropriate identification keys to species level in two different ecological regions of plains and mountain in 4 seasons in 2015. Results: Totally 492 ticks from cattle, sheep, and goats in 34 herds were collected. Totally, 18.53 of domestic animals were infected by ticks. All ticks were belonged to family Ixodidae and classified into three genera and six species comprising Hyalomma anatolicum (38.83), Hy. Asiaticum (23.37), Hy. marginatum (2.85), Hy. sp. (3.45), Rhipicephalus sanguineus (14.02) and Haemaphysalis sulcata (10.98). Sex ratio of the collected specimens showed 241 (48.99) male, 219 (44.51) female and 32 (6.5) nymph Conclusion: Studied area is important for production of livestock and dairy products. Annually, many livestock products are exported to other parts from this region; therefore, it is very important to identify the infection rate of tick-borne diseases as well as safety factors on livestock. © 2018, Iranian Journal of Public Health. All rights reserved
Hyalomma anatolicum as the main infesting tick in an important livestock rearing region, central area of iran
Background: This study was carried out to determine the infestation of domestic ruminants to ticks in an important livestock-rearing region, located in central part of Iran. Methods: Ticks were collected from cattle, sheep, and goats and then were identified with appropriate identification keys to species level in two different ecological regions of plains and mountain in 4 seasons in 2015. Results: Totally 492 ticks from cattle, sheep, and goats in 34 herds were collected. Totally, 18.53 of domestic animals were infected by ticks. All ticks were belonged to family Ixodidae and classified into three genera and six species comprising Hyalomma anatolicum (38.83), Hy. Asiaticum (23.37), Hy. marginatum (2.85), Hy. sp. (3.45), Rhipicephalus sanguineus (14.02) and Haemaphysalis sulcata (10.98). Sex ratio of the collected specimens showed 241 (48.99) male, 219 (44.51) female and 32 (6.5) nymph Conclusion: Studied area is important for production of livestock and dairy products. Annually, many livestock products are exported to other parts from this region; therefore, it is very important to identify the infection rate of tick-borne diseases as well as safety factors on livestock. © 2018, Iranian Journal of Public Health. All rights reserved
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The ability of analysts’ recommendations to predict optimistic and pessimistic forecasts
Previous researches show that buy (growth) companies conduct income increasing earnings management in order to meet forecasts and generate positive forecast Errors (FEs). This behavior however, is not inherent in sell (non-growth) companies. Using the aforementioned background, this research hypothesizes that since sell companies are pressured to avoid income increasing earnings management, they are capable, and in fact more inclined, to pursue income decreasing Forecast Management (FM) with the purpose of generating positive FEs. Using a sample of 6553 firm-years of companies that are listed in the NYSE between the years 2005–2010, the study determines that sell companies conduct income decreasing FM to generate positive FEs. However, the frequency of positive FEs of sell companies does not exceed that of buy companies. Using the efficiency perspective, the study suggests that even though buy and sell companies have immense motivation in avoiding negative FEs, they exploit different but efficient strategies, respectively, in order to meet forecasts. Furthermore, the findings illuminated the complexities behind informative and opportunistic forecasts that falls under the efficiency
versus opportunistic theories in literature
A soft computing system using intelligent imputation strategies for roughness prediction in deep drilling
Microenvironmental Modulation of Decorin and Lumican in Temozolomide-Resistant Glioblastoma and Neuroblastoma Cancer Stem-Like Cells
The presence of cancer stem cells (CSCs) or tumor-initiating cells can lead to cancer recurrence in a permissive cell–microenvironment interplay, promoting invasion in glioblastoma (GBM) and neuroblastoma (NB). Extracellular matrix (ECM) small leucine-rich proteoglycans (SLRPs) play multiple roles in tissue homeostasis by remodeling the extracellular matrix (ECM) components and modulating intracellular signaling pathways. Due to their pan-inhibitory properties against receptor tyrosine kinases (RTKs), SLRPs are reported to exert anticancer effects in vitro and in vivo. However, their roles seem to be tissue-specific and they are also involved in cancer cell migration and drug resistance, paving the way to complex different scenarios. The aim of this study was to determine whether the SLRPs decorin (DCN) and lumican (LUM) are recruited in cell plasticity and microenvironmental adaptation of differentiated cancer cells induced towards stem-like phenotype. Floating neurospheres were generated by applying CSC enrichment medium (neural stem cell serum-free medium, NSC SFM) to the established SF-268 and SK-N-SH cancer cell lines, cellular models of GBM and NB, respectively. In both models, the time-dependent synergistic activation of DCN and LUM was observed. The highest DCN and LUM mRNA/protein expression was detected after cell exposure to NSC SFM for 8/12 days, considering these cells as SLRP-expressing (SLRP+) CSC-like. Ultrastructural imaging showed the cellular heterogeneity of both the GBM and NB neurospheres and identified the inner living cells. Parental cell lines of both GBM and NB grew only in soft agar + NSC SFM, whereas the secondary neurospheres (originated from SLRP+ t8 CSC-like) showed lower proliferation rates than primary neurospheres. Interestingly, the SLRP+ CSC-like from the GBM and NB neurospheres were resistant to temozolomide (TMZ) at concentrations >750 μM. Our results suggest that GBM and NB CSC-like promote the activation of huge quantities of SLRP in response to CSC enrichment, simultaneously acquiring TMZ resistance, cellular heterogeneity, and a quiescent phenotype, suggesting a novel pivotal role for SLRP in drug resistance and cell plasticity of CSC-like, allowing cell survival and ECM/niche modulation potential.This study was supported by Fundació la Marató TV3, Project n° 111431
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ICRF heating on TFTR-effect on stability and performance
With the addition of two new antennas and two radiofrequency (RF) generators, the TFTR ICRF system is complete. The total complement of four antennas and six generators is designed for 12.5 MW operation. Experiments with this system have been performed recently on TFTR in the low recycling regime to increase the performance of supershot plasmas, in a non-resonant regime to explore electron heating, and in high recycling discharges with energetic ion tails to simulate fusion alpha particles. Noteworthy results include: direct electron heating observed with absorption rates in agreement with theory; electron heating of supershot plasmas ([Delta]TEO [approximately] 2 key) via energetic ion tails that would increase the pressure of the alpha particles in DT plasmas; and the first observation of the toroidal Alfven eigenmode (TAE) instability driven by the energetic ion tail in hydrogen minority heating
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