8,659 research outputs found

    Numerical analysis of a relaxed variational model of hysteresis in two-phase solids

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    This paper presents the numerical analysis for a variational formulation of rate-independent phase transformations in elastic solids due to Mielke et al. The new model itself suggests an implicit time-discretization which is combined with the finite element method in space. A priori error estimates are established for the quasioptimal spatial approximation of the stress field within one time-step. A posteriori error estimates motivate an adaptive mesh-refining algorithm for efficient discretization. The proposed scheme enables numerical simulations which show that the model allows for hysteresis

    [Report of] Specialist Committee V.4: ocean, wind and wave energy utilization

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    The committee's mandate was :Concern for structural design of ocean energy utilization devices, such as offshore wind turbines, support structures and fixed or floating wave and tidal energy converters. Attention shall be given to the interaction between the load and the structural response and shall include due consideration of the stochastic nature of the waves, current and wind

    Composition, volume, and aspect ratio dependence of the strain distribution, band lineups and electron effective masses in self-assembled pyramidal In1-xGaxAs/GaAs and SixGe1-x/Si quantum dots

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    We present a systematic investigation of the strain distribution of self-assembled pyramidal In1-xGaxAs/GaAs and SixGe1-x/Si quantum dots for the case of growth on a (001) substrate. The dependence of the biaxial and hydrostatic components of the strain on the quantum dot volume, aspect ratio, composition, and percentage of alloying x is studied using a method based on a Green's function technique. The dependence of the carriers' confining potentials and the electronic effective mass on the same parameters is then calculated in the framework of eight-band k .p theory. The results for which comparable published data are available are in good agreement with the theoretical values for strain profiles, confining potentials, and electronic effective mass. © 2002 American Institute of Physics

    The impact of fire on habitat use by the short-snouted elephant shrew ('Elephantulus brachyrhynchus') in North West Province, South Africa

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    Several studies have investigated the response of small mammal populations to fire, but few have investigated behavioural responses to habitat modification. In this study we investigated the impact of fire on home range, habitat use and activity patterns of the short-snouted elephant shrew (Elephantulus brachyrhynchus) by radio-tracking individuals before and after a fire event. All animals survived the passage of fire in termite mound refugia. Before the fire, grassland was used more than thickets, but habitat utilization shifted to thickets after fire had removed the grass cover. Thickets were an important refuge both pre- and post-fire, but the proportion of thicket within the home range was greater post-fire. We conclude that fire-induced habitat modification resulted in a restriction of E. brachyrhynchus movements to patches of unburned vegetation. This may be a behavioural response to an increase in predation pressure associated with a reduction in cover, rather than a lack of food. This study highlights the importance of considering the landscape mosaic in fire management and allowing sufficient island patches to remain post-fire ensures the persistence of the small mammal fauna

    Post-Transplant Outcomes in High-Risk Compared with Non-High-Risk Multiple Myeloma: A CIBMTR Analysis.

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    Conventional cytogenetics and interphase fluorescence in situ hybridization (FISH) identify high-risk multiple myeloma (HRM) populations characterized by poor outcomes. We analyzed these differences among HRM versus non-HRM populations after upfront autologous hematopoietic cell transplantation (autoHCT). Between 2008 and 2012, 715 patients with multiple myeloma identified by FISH and/or cytogenetic data with upfront autoHCT were identified in the Center for International Blood and Marrow Transplant Research database. HRM was defined as del17p, t(4;14), t(14;16), hypodiploidy (-Y) or chromosome 1 p and 1q abnormalities; all others were non-HRM. Among 125 HRM patients (17.5%), induction with bortezomib and immunomodulatory agents (imids) was higher compared with non-HRM (56% versus 43%, P \u3c .001) with similar pretransplant complete response (CR) rates (14% versus 16%, P .1). At day 100 post-transplant, at least a very good partial response was 59% in HRM and 61% in non-HRM (P = .6). More HRM patients received post-transplant therapy with bortezomib and imids (26% versus 12%, P = .004). Three-year post-transplant progression-free (PFS) and overall survival (OS) rates in HRM versus non-HRM were 37% versus 49% (P \u3c .001) and 72% versus 85% (P \u3c .001), respectively. At 3 years, PFS for HRM patients with and without post-transplant therapy was 46% (95% confidence interval [CI], 33 to 59) versus 14% (95% CI, 4 to 29) and in non-HRM patients with and without post-transplant therapy 55% (95% CI, 49 to 62) versus 39% (95% CI, 32 to 47); rates of OS for HRM patients with and without post-transplant therapy were 81% (95% CI, 70 to 90) versus 48% (95% CI, 30 to 65) compared with 88% (95% CI, 84 to 92) and 79% (95% CI, 73 to 85) in non-HRM patients with and without post-transplant therapy, respectively. Among patients receiving post-transplant therapy, there was no difference in OS between HRM and non-HRM (P = .08). In addition to HRM, higher stage, less than a CR pretransplant, lack of post-transplant therapy, and African American race were associated with worse OS. In conclusion, we show HRM patients achieve similar day 100 post-transplant responses compared with non-HRM patients, but these responses are not sustained. Post-transplant therapy appeared to improve the poor outcomes of HRM

    PHYTOCHEMICAL PROFILE WITH ANTI-TUMOR ACTIVITY ESTIMATION OF CRUDE EXTRACT, ESSENTIAL OIL AND D-LIMONENE FROM CITRUS AURANTIUM L. AGAINST EHRLICH CARCINOMA

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    Objective: Plant based drugs have been a solution in the search for more cost-effective and less harmful drugs for the treatment of neoplasia. Citrus aurantium L. (Rutaceae) is abundant in Brazil and D-limonene, a monoterpene used in the prevention and treatment of neoplasia, was identified as a major compound in the oil of this specie. Objective of current study includes estimation of anti-tumor activity of Citrus aurantium L. (Rutaceae) (crude extract, essential oil and D-limonene) against Ehrlich carcinoma, as well as their phytochemical evaluation (D-limonene and essential oil). Methods: There was a randomized non-clinical trial in which were used adult male mice (Balb-C). Four groups of animals were used having 6 numbers of animal in each group. All groups were inoculated with the Ehrlich tumor and then received the treatment (control, crude extract, essential oil and D-limonene) by oral route daily (28 day treatment). Essential oil was obtained by hydro-distillation and analyzed by the means of GC (Gas Chromatography) that was attached to mass spectrometry. In last of the observations  hemogram was obtained. Results: Animals treated with the essential oil has shown no significant difference compared to the group treated with D-limonene. The group treated with crude extract had a growth inhibition close to the essential oil and D-limonene groups. Conclusion: It´s concluded that the essential oil and the crude extract of Citrus aurantium, L. (Rutaceae) can become therapeutic agents because of their anti-tumor activity with no toxicity to the blood cells and have low cost of production. Further studies are necessary, so they can be used in the treatment of neoplasia in humans. The chromatographic and spectrometric analyzes indicated the presence of other components in smaller amounts in the essential oil, which suggests that they could have a synergic activity to the D-limonene.                           Peer Review History: Received 2 June 2020; Revised 25 June; Accepted 4 July, Available online 15 July 2020 Academic Editor: Dr. Muhammad Zahid Iqbal, AIMST University, Malaysia, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Ahmad Najib, Universitas Muslim Indonesia, Makassar, Indonesia, [email protected] Dr. Mohamed Said Fathy Al-Refaey, University of Sadat City, Menofia, Egypt, [email protected]  Similar Articles: CYTOTOXIC EFFECT AND PHYTOCHEMICAL STUDY OF PETROLEUM ETHER EXTRACT OF TILIA CORDATA MIL

    Impairing the production of ribosomal RNA activates mammalian target of rapamycin complex 1 signalling and downstream translation factors

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    Ribosome biogenesis is a key process for maintaining protein synthetic capacity in dividing or growing cells, and requires coordinated production of ribosomal proteins and ribosomal RNA (rRNA), including the processing of the latter. Signalling through mammalian target of rapamycin complex 1 (mTORC1) activates all these processes. Here, we show that, in human cells, impaired rRNA processing, caused by expressing an interfering mutant of BOP1 or by knocking down components of the PeBoW complex elicits activation of mTORC1 signalling. This leads to enhanced phosphorylation of its substrates S6K1 and 4E-BP1, and stimulation of proteins involved in translation initiation and elongation. In particular, we observe both inactivation and downregulation of the eukaryotic elongation factor 2 kinase, which normally inhibits translation elongation. The latter effect involves decreased expression of the eEF2K mRNA. The mRNAs for ribosomal proteins, whose translation is positively regulated by mTORC1 signalling, also remain associated with ribosomes. Therefore, our data demonstrate that disrupting rRNA production activates mTORC1 signalling to enhance the efficiency of the translational machinery, likely to help compensate for impaired ribosome production

    Experimental observation of spatial antibunching of photons

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    We report an interference experiment that shows transverse spatial antibunching of photons. Using collinear parametric down-conversion in a Young-type fourth-order interference setup we show interference patterns that violate the classical Schwarz inequality and should not exist at all in a classical description.Comment: 4 pages, 7 figure

    Multi-Phase Equilibrium of Crystalline Solids

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    A continuum model of crystalline solid equilibrium is presented in which the underlying periodic lattice structure is taken explicitly into account. This model also allows for both point and line defects in the bulk of the lattice and at interfaces, and the kinematics of such defects is discussed in some detail. A Gibbsian variational argument is used to derive the necessary bulk and interfacial conditions for multi-phase equilibrium (crystal-crystal and crystal-melt) where the allowed lattice variations involve the creation and transport of defects in the bulk and at the phase interface. An interfacial energy, assumed to depend on the interfacial dislocation density and the orientation of the interface with respect to the lattices of both phases, is also included in the analysis. Previous equilibrium results based on nonlinear elastic models for incoherent and coherent interfaces are recovered as special cases for when the lattice distortion is constrained to coincide with the macroscopic deformation gradient, thereby excluding bulk dislocations. The formulation is purely spatial and needs no recourse to a fixed reference configuration or an elastic-plastic decomposition of the strain. Such a decomposition can be introduced however through an incremental elastic deformation superposed onto an already dislocated state, but leads to additional equilibrium conditions. The presentation emphasizes the role of {configurational forces} as they provide a natural framework for the description and interpretation of singularities and phase transitions.Comment: 32 pages, to appear in Journal of the Mechanics and Physics of Solid
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