670 research outputs found
A medida do erro em índices de custo de vida
Se a teoria dos números-índices é rica em discussões da maior ou menor adequação de certas formulações conceituais desses índices, é totalmente pobre em termos da discussão dos erros existentes na elaboração de qualquer um deles
Estimação do relativo de preços de produto homogêneo
Na elaboração de um índice de preços ao consumidor (próxis do custo de vida) aparece constantemente a dúvida sobre a melhor forma de estimação do relativo de preços
Receding Horizon Re-ordering of Multi-Agent Execution Schedules
The trajectory planning for a fleet of Automated Guided Vehicles (AGVs) on a
roadmap is commonly referred to as the Multi-Agent Path Finding (MAPF) problem,
the solution to which dictates each AGV's spatial and temporal location until
it reaches it's goal without collision. When executing MAPF plans in dynamic
workspaces, AGVs can be frequently delayed, e.g., due to encounters with humans
or third-party vehicles. If the remainder of the AGVs keeps following their
individual plans, synchrony of the fleet is lost and some AGVs may pass through
roadmap intersections in a different order than originally planned. Although
this could reduce the cumulative route completion time of the AGVs, generally,
a change in the original ordering can cause conflicts such as deadlocks. In
practice, synchrony is therefore often enforced by using a MAPF execution
policy employing, e.g., an Action Dependency Graph (ADG) to maintain ordering.
To safely re-order without introducing deadlocks, we present the concept of the
Switchable Action Dependency Graph (SADG). Using the SADG, we formulate a
comparatively low-dimensional Mixed-Integer Linear Program (MILP) that
repeatedly re-orders AGVs in a recursively feasible manner, thus maintaining
deadlock-free guarantees, while dynamically minimizing the cumulative route
completion time of all AGVs. Various simulations validate the efficiency of our
approach when compared to the original ADG method as well as robust MAPF
solution approaches.Comment: IEEE Transactions on Robotics (T-Ro) preprint, 17 pages, 32 figure
Resonance-enhanced vibrational spectroscopy of molecules on a superconductor
Molecular vibrational spectroscopy with the scanning tunneling microscope is
feasible but usually detects few vibrational modes. We harness sharp
Yu-Shiba-Rusinov (YSR) states observed from molecules on a superconductor to
significantly enhance the vibrational signal. From a lead phthalocyanin
molecule 46 vibrational peaks are resolved enabling a comparison with
calculated modes. The energy resolution is improved beyond the thermal
broadening limit and shifts induced by neighbor molecules or the position of
the microscope tip are determined. Vice versa, spectra of vibrational modes are
used to measure the effect of an electrical field on the energy of YSR states.
The method may help to further probe the interaction of molecules with their
environment and to better understand selection rules for vibrational
excitations
No Incidence of BRAF Mutations in Salivary Gland Carcinomas—Implications for Anti-EGFR Therapies
BRAF is the main effector of KRAS in the RAS-RAF-MAPK axis, a signaling pathway downstream of EGFR. The activation of this cascade is an important pathway in cancer development and is considered a key pathway for therapeutic molecules. Recent studies in metastatic colorectal cancer found that an oncogenic activation of BRAF by a point mutation in exon 15 (V600E) could bypass the EGFR-initiated signaling cascade with the effect that patients bearing the mutant BRAF allele are not likely to benefit from EGFR-targeted therapies. We designed an allele-specific PCR and screened 65 salivary gland carcinoma (SGC) of the main histopathological types for the BRAF V600E mutation. All 65 SGC in this cohort (100%) presented the BRAF wildtype. In a previous study, we found a KRAS wildtype in 98.5% of SGC.
These findings imply that SGC rarely acquires mutations that result in a constitutive activation of the signaling cascade downstream of EGFR and this pleads in favor of further therapeutic trials with EGFR-targeting monoclonal
antibodies
Endovascular Intervention for Critical Lower Limb Ischemia; a Review of Outcomes after Percutaneous Transluminal Angioplasty using Balloon Catheter
Peripheral Arterial Disease (PAD) of lower limb with variable morbidity can be manifested as an asymptomatic, sever or life threatening disease. It is also a major cause of disability in many cases. The management of patients with PAD can be defined from a number of different treatment options in the terms of conservative-, interventional- and surgical therapies.Percutaneous Transluminal Angioplasty (PTA) using balloon catheter as a revascularization procedure has been used with acceptable outcomes. The method results are highlighted with comparable success—and patency rates, low complications, improving the quality of life and survival. We reviewed published studies and found that PTA is an appropriate alternative in the management of patient with Critical Limb Ischemia (CLI). Better outcomes have been achieved using Drug Coated Balloons (DCB) as well as Drug Eluting Stents (DES). Atherectomy remains with controversial results. Patient characteristics, the presence of associated risk factors, characteristics of lesions and accompanied cardiopulmonary disease may be the main challenges to use of these treatment options in the future
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