310 research outputs found

    Object Reconfiguration with Dextrous Robot Agents

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    This paper addresses an object manipulation planning algorithm for dextrous robot systems consisting a multifingered hand and a robotic manipulator. A method has been developed for object reconfiguration design. The result is a new algorithm using artificial intelligence based on simulated annealing and A* search. The upper level of the manipulation system, the global planner generates the motion of the object. The lower level, the local planner deals with the motion of the agents relative to the object and the design of the contact forces. The local planner is based on simulated annealing, thus the the local minima can be avoided in the energy function of the motion with high probability. Application of the algorithm has been discussed for three robot arms

    Designing Comprehensive Partnering Agreements

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    Agreements are a key mechanism of partnerships because their role is to govern interactions. They help partnerships become more effective by allowing partners to cope with relational, performance and situational risks that characterise inter-organisational relationships. The Partnerships Resource Centre and The Partnering Initiative have developed a Partnering Agreement Scorecard based on insights from practice and grounded on theory. The tool will be of value to any organisation that contemplates setting up a new or reviewing an existing partnership. It offers a structure for generating and assessing an agreement which should fit the initial needs of most partnerships. It is our experience that addressing a number of questions in a more systematic manner seriously increases the chances of success – by ensuring all partners are on the same page, that the partnership has been set up correctly, by helping to keep a partnership on track and by providing guidance also in difficult times. As accompaniment the publication Designing Comprehensive Partnering Agreements: An Introduction to the Partnering Agreements Scorecard, provides shorthand of the most critical questions that should be addressed when developing a partnership agreement. This guide includes both an overview of the nature and value of agreements and a new tool for their construction and review

    One-loop approximation of Moller scattering in Krein-space quantization

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    It has been shown that the negative-norm states necessarily appear in a covariant quantization of the free minimally coupled scalar field in de Sitter spacetime [1,2]. In this processes ultraviolet and infrared divergences have been automatically eliminated [3]. A natural renormalization of the one-loop interacting quantum field in Minkowski spacetime (λϕ4\lambda\phi^4) has been achieved through the consideration of the negative-norm states defined in Krein space. It has been shown that the combination of quantum field theory in Krein space together with consideration of quantum metric fluctuation, results in quantum field theory without any divergences [4]. Pursuing this approach, we express Wick's theorem and calculate M{\o}ller scattering in the one-loop approximation in Krein space. The mathematical consequence of this method is the disappearance of the ultraviolet divergence in the one-loop approximation.Comment: 10 page

    Spherical Solutions due to the Exterior Geometry of a Charged Weyl Black Hole

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    Firstly we derive peculiar spherical Weyl solutions, using a general spherically symmetric metric due to a massive charged object with definite mass and radius. Afterwards, we present new analytical solutions for relevant cosmological terms, which appear in the metrics. Connecting the metrics to a new geometric definition of a charged Black Hole, we numerically investigate the effective potentials of the total dynamical system, considering massive and massless test particles, moving on such Black Holes.Comment: 8 pages, 5 figure

    Dynamics of porous and amorphous magnesium borohydride to understand solid state Mg-ion-conductors

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    Rechargeable solid-state magnesium batteries are considered for high energy density storage and usage in mobile applications as well as to store energy from intermittent energy sources, triggering intense research for suitable electrode and electrolyte materials. Recently, magnesium borohydride, Mg(BH4_{4})2_{2}, was found to be an effective precursor for solid-state Mg-ion conductors. During the mechanochemical synthesis of these Mg-ion conductors, amorphous Mg(BH4_{4})2_{2} is typically formed and it was postulated that this amorphous phase promotes the conductivity. Here, electrochemical impedance spectroscopy of as-received γ-Mg(BH4_{4})2_{2} and ball milled, amorphous Mg(BH4_{4})2_{2} confirmed that the conductivity of the latter is ~2 orders of magnitude higher than in as-received γ-Mg(BH4_{4})2_{2} at 353 K. Pair distribution function (PDF) analysis of the local structure shows striking similarities up to a length scale of 5.1 Å, suggesting similar conduction pathways in both the crystalline and amorphous sample. Up to 12.27 Å the PDF indicates that a 3D net of interpenetrating channels might still be present in the amorphous phase although less ordered compared to the as-received γ-phase. However, quasi elastic neutron scattering experiments (QENS) were used to study the rotational mobility of the [BH4_{4}] units, revealing a much larger fraction of activated [BH4_{4}] rotations in amorphous Mg(BH4_{4})2_{2}. These findings suggest that the conduction process in amorphous Mg(BH4_{4})2_{2} is supported by stronger rotational mobility, which is proposed to be the so-called “paddle-wheel” mechanism

    The link between plant-based diet indices with biochemical markers of bone turn over, inflammation, and insulin in Iranian older adults

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    Background: The association of plant-based diets and biomarkers of bone, insulin, and inflammation is still unclear. Objectives: We investigated the associations between biomarkers of bone, insulin, and inflammation and three plant-based diet indices: an overall plant-based diet index (PDI); a healthy plant-based diet index (hPDI); and an unhealthy plant-based diet index (uPDI). Methods: We included 178 elderly subjects who referred to health centers in Tehran. Blood and urine samples were collected to measure osteocalcin. The Human C-telopeptide of type â collagen (u-CTX-I), highly sensitive C-reactive protein (hs-CRP), parathyroid hormone (PTH), 25(OH) D, and insulin resistance and sensitivity. We created an overall PDI, hPDI, and uPDI from semi-quantitative food frequency questionnaire (FFQ) data. Results: Dietary groups of Vegetables (r =.15, p =.03), nuts (r =.16, p =.03), dairy (r =.25, p =.001), eggs (r =.27, p <.001), red meat, and animal products (r =.25, p =.001) were directly correlated with osteocalcin. Refined grains were also had a positive association with serum insulin concentration (r =.14, p =.04). PTH levels are inversely associated with PDI score (β = â��0.18, p =.01). Also, serum insulin concentration was negatively associated with PDI score (β = â��0.10, p =.04). Urine CTX-1 levels were significantly associated with hPDI score (β = â��0.06, p =.04). u-CTX-1 levels are inversely associated with uPDI score. This significance did not change with the adjustment of the confounders (β = â��0.28, p <.001). Conclusions: More adherence to PDI and hPDI and less in uPDI may have a beneficial effect on biomarkers of bone, inflammation, and insulin thus preserving chronic diseases. © 2021 The Authors. Food Science & Nutrition published by Wiley Periodicals LL

    Human papilloma virus and breast cancer: The role of inflammation and viral expressed proteins

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    Background: Breast cancer is currently the most common neoplasm diagnosed in women globally. There is a growing body of evidence to suggest that human papillomavirus (HPV) infection may play a key role in invasiveness of breast cancer. The aim of this study was to determine the presence of HPV in patients with breast cancer and its possible association with cancer progression. Methods: Breast specimens were collected from 72 patients with breast cancer and 31 healthy controls. The presence of HPV was investigated by polymerase chain reaction (PCR) and genotyping was performed for positive cases. We also evaluated the viral factors such as E6, E2, and E7 in HPV positive cases. Enzyme-linked immunosorbent assay (ELISA (and Real-time PCR techniques were used to measure the expression level of anti-carcinogenic genes, such as p53, retinoblastoma (RB), breast and ovarian cancer susceptibility gene (BRCA1, BRCA2) and inflammatory cytokines, including tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), nuclear factor-kB (NF-kB), and different interleukins [ILs] (IL-1,IL6, and IL-17). Results: The HPV DNA was detected in 48.6% of breast cancer samples, whereas only 16.1% of controls were positive for HPV. We observed statistically significant differences between breast cancer patients and HPV presence (P = 0.003). HPV type 18 was the most prevalent virus genotype in patients. The expression of P53, RB, BRCA1, and BRCA2 were decreased in patients with HPV-positive breast cancer as compared to HPV-negative breast cancer and healthy controls. (All P-values were less than 0.05). The presence of the HPV was associated with increased inflammatory cytokines (IL-1, IL-6, IL-17, TGF-β, TNF-α, and NF-kB) and tumor progression. Conclusion: The present study demonstrated that HPV infection may implicate in the development of some types of breast cance

    Human papilloma virus and breast cancer: The role of inflammation and viral expressed proteins

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    Background: Breast cancer is currently the most common neoplasm diagnosed in women globally. There is a growing body of evidence to suggest that human papillomavirus (HPV) infection may play a key role in invasiveness of breast cancer. The aim of this study was to determine the presence of HPV in patients with breast cancer and its possible association with cancer progression. Methods: Breast specimens were collected from 72 patients with breast cancer and 31 healthy controls. The presence of HPV was investigated by polymerase chain reaction (PCR) and genotyping was performed for positive cases. We also evaluated the viral factors such as E6, E2, and E7 in HPV positive cases. Enzyme-linked immunosorbent assay (ELISA (and Real-time PCR techniques were used to measure the expression level of anti-carcinogenic genes, such as p53, retinoblastoma (RB), breast and ovarian cancer susceptibility gene (BRCA1, BRCA2) and inflammatory cytokines, including tumor necrosis factor α (TNF-α), transforming growth factor β (TGF-β), nuclear factor-kB (NF-kB), and different interleukins ILs (IL-1,IL6, and IL-17). Results: The HPV DNA was detected in 48.6% of breast cancer samples, whereas only 16.1% of controls were positive for HPV. We observed statistically significant differences between breast cancer patients and HPV presence (P = 0.003). HPV type 18 was the most prevalent virus genotype in patients. The expression of P53, RB, BRCA1, and BRCA2 were decreased in patients with HPV-positive breast cancer as compared to HPV-negative breast cancer and healthy controls. (All P-values were less than 0.05). The presence of the HPV was associated with increased inflammatory cytokines (IL-1, IL-6, IL-17, TGF-β, TNF-α, and NF-kB) and tumor progression. Conclusion: The present study demonstrated that HPV infection may implicate in the development of some types of breast cancer. © 2019 The Author(s)
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