8,664 research outputs found
Emerging role of nuclear factor erythroid 2-related factor 2 in the mechanism of action and resistance to anticancer therapies
Nuclear factor E2-related factor 2 (NRF2), a transcription factor, is a master regulator of an array of genes related to oxidative and electrophilic stress that promote and maintain redox homeostasis. NRF2 function is well studied in in vitro, animal and general physiology models. However, emerging data has uncovered novel functionality of this transcription factor in human diseases such as cancer, autism, anxiety disorders and diabetes. A key finding in these emerging roles has been its constitutive upregulation in multiple cancers promoting pro-survival phenotypes. The survivability pathways in these studies were mostly explained by classical NRF2 activation involving KEAP-1 relief and transcriptional induction of reactive oxygen species (ROS) neutralizing and cytoprotective drug-metabolizing enzymes (phase I, II, III and 0). Further, NRF2 status and activation is associated with lowered cancer therapeutic efficacy and the eventual emergence of therapeutic resistance. Interestingly, we and others have provided further evidence of direct NRF2 regulation of anticancer drug targets like receptor tyrosine kinases and DNA damage and repair proteins and kinases with implications for therapy outcome. This novel finding demonstrates a renewed role of NRF2 as a key modulatory factor informing anticancer therapeutic outcomes, which extends beyond its described classical role as a ROS regulator. This review will provide a knowledge base for these emerging roles of NRF2 in anticancer therapies involving feedback and feed forward models and will consolidate and present such findings in a systematic manner. This places NRF2 as a key determinant of action, effectiveness and resistance to anticancer therapy
Anti-inflammatory and analgesic activity of water extract from Ipomoea asarifolia Desr (Convolvulaceae)
Ipomoea asarifolia (IA) (Desr) (family: Convolvulacea) is an herb, with a hairless succulent perennial stem, trailing on the ground usually several meters long. The various parts of this plant are used locally in the alleviation of inflammation and painful conditions. This study was done to evaluate the antiinflammatory and analgesic activities of the water extract of the plant in experimental animal models (anti-inflammatory action by carrageenan-induced rat paw edema, the analgesic activity by acetic acid-induced writhing response method. The water extract of I. asarifolia in doses of 37.5, 75 and 150 mg/kg showed 64.7, 70.5 and 73.6% inhibition of paw edema, respectively, at the end of 3 h and in acetic-induced writhing, the percentage protection was 45, 58.1, and 60.7%, respectively. These showed dosedependent action in all the experimental models. The present study indicates that I. asarifolia has significant anti-inflammatory and analgesic properties.Keywords: Ipomoea asarifolia, anti-inflammatory activity, rat paw oedema, antinociceptive activity, pain model
Reconsidering Policy Implementation of Vocational Technical Education using 6-3-3-4 System of Education in Curbing Societal Problems
Vocational and Technical education as preserved in the Nigerian national policy on education, is connected with producing adequate and qualitative technological human resources directed towards a producing of trained, experienced and self-reliant craftsmen, technologists and technicians in the field of technical and vocational education for the general development of the country and its citizenry. However, the training of technical personnel has witnessed many hindrances and challenges originating from unrealistic policies, unclear curriculum that has little correlation with the needs of the society. In addition, misappropriation of fund meant for education development purposes, lack of qualified teachers, inadequate funding and cases of bribery and corruption are all connected to the poor implementation of the policy. This paper is aimed at providing a rethink in the implementation of 6334 system of education by examining the issues, challenges and the way forward in curbing out societal problems through Vocational and Technical Education
Past, present and future of path-planning algorithms for mobile robot navigation in dynamic environments
Mobile robots have been making a significant contribution to the advancement of many sectors including automation of mining, space, surveillance, military, health, agriculture and many more. Safe and efficient navigation is a fundamental requirement of mobile robots, thus, the demand for advanced algorithms rapidly increased. Mobile robot navigation encompasses the following four requirements: perception, localization, path-planning and motion control. Among those, path-planning is a vital part of a fast, secure operation. During the last couple of decades, many path-planning algorithms were developed. Despite most of the mobile robot applications being in dynamic environments, the number of algorithms capable of navigating robots in dynamic environments is limited. This paper presents a qualitative comparative study of the up-to-date mobile robot path-planning methods capable of navigating robots in dynamic environments. The paper discusses both classical and heuristic methods including artificial potential field, genetic algorithm, fuzzy logic, neural networks, artificial bee colony, particle swarm optimization, bacterial foraging optimization, ant-colony and Agoraphilic algorithm. The general advantages and disadvantages of each method are discussed. Furthermore, the commonly used state-of-the-art methods are critically analyzed based on six performance criteria: algorithm's ability to navigate in dynamically cluttered areas, moving goal hunting ability, object tracking ability, object path prediction ability, incorporating the obstacle velocity in the decision, validation by simulation and experimentation. This investigation benefits researchers in choosing suitable path-planning methods for different applications as well as identifying gaps in this field. © 2020 IEEE
The neutralino projector formalism for complex SUSY parameters
We present a new formalism describing the neutralino physics in the context
of the minimal supersymmetric model (MSSM), where CP violation induced by
complex and parameters is allowed. The formalism is based on the
construction of neutralino projectors, and can be directly generalized to
non-minimal SUSY models involving any number of neutralinos. It extends a
previous work applied to the real SUSY parameter case. In MSSM, the method
allows to describe all physical observables related to a specific neutralino,
in terms of its
CP eigenphase and three complex numbers called its "reduced projector
elements".
As the experimental knowledge on the neutralino-chargino sectors will be
being accumulated, the problem of extracting the various SUSY parameters will
arise. Motivated by this, we consider various scenarios concerning the
quantities that could be first measured. Analytical disentangled expressions
determining the related SUSY parameters from them, are then derived, which also
emphasize the efficiency of the formalism.Comment: Version accepted in Phys. Rev. D. e-mail: [email protected]
ActivityNET: Neural networks to predict public transport trip purposes from individual smart card data and POIs
Predicting trip purpose from comprehensive and continuous smart card data is beneficial for transport and city planners in investigating travel behaviors and urban mobility. Here, we propose a framework, ActivityNET, using Machine Learning (ML) algorithms to predict passengers’ trip purpose from Smart Card (SC) data and Points-of-Interest (POIs) data. The feasibility of the framework is demonstrated in two phases. Phase I focuses on extracting activities from individuals’ daily travel patterns from smart card data and combining them with POIs using the proposed “activity-POIs consolidation algorithm”. Phase II feeds the extracted features into an Artificial Neural Network (ANN) with multiple scenarios and predicts trip purpose under primary activities (home and work) and secondary activities (entertainment, eating, shopping, child drop-offs/pick-ups and part-time work) with high accuracy. As a case study, the proposed ActivityNET framework is applied in Greater London and illustrates a robust competence to predict trip purpose. The promising outcomes demonstrate that the cost-effective framework offers high predictive accuracy and valuable insights into transport planning
Aplikasi Udara Dingin Vortex Tubepada Pembubutan Baja ST 41 Menggunakan Pahat HSS
Pahat merupakan komponen utama dalam proses pemesinan selain mesin bubut dan benda kerja. Umur pahat merupakan suatu data pemesinan yang sangat penting dalam perencanaan pemesinan. Vortextube merupakan alat yang dapat memisahkan aliran udara yang bertekanan menjadi udara panas dan dingin. Dalam penelitian ini pengaruh kecepatan potong, gerak makan, dan kedalaman potong terhadap keausan pahat yang digunakan akan diteliti. Metode Taguchi digunakan menganalisa faktor yang paling berpengaruh signifikan terhadap keausan. Pada penelitian ini akan dianalisis secara kualitatif (grafik) dan kuantitatif (statistic) dengan metode analisa varian (ANOVA). Dalam penelitian ini, proses pembubutan menggunakan pahat HSS dan material benda kerja baja ST 41. Dalam proses pengujian, gerak makan (f) yang digunakan adalah 0,09 mm/rev, 0,12 mm/rev,0,18 mm/rev, sedangkan kecepatan potong (v) yang digunakan adalah 58,72 mm/min, 86,35 m/min, 113,25 m/min dan untuk kedalaman potong (a) 1,0 mm, 1,5 mm, 2,0 mm. Udara dingin vortextube yang sudah ada dilakukan pada penelitian sebelumnya yaitu suhu 15º dan tekanan udara 5 bar/psi. Dari analisa varian yang dilakukan, kecepatan potong memiliki pengaruh signifikan terhadap keausan pahat. Kondisi parameter pemesinan yang optimal diperoleh pada kecepatan potong (v): 58,72, gerak makan (f) 0,09 mm/rev dan kedalaman potong (a) : 1,0 mm dengan umur pahat mencapai 139 menit. Laju keausan tepi pahat semakin meningkat dengan bertambahnya kecepatan potong. Dari analisa S/N ratio diperoleh parameter pemesinan yang memiliki pengaruh signifikan terhadap keausan pahat adalah kecepatan potong dengan nilai kontribusi = 0,024 karena tidak melebihi > 0,05
Analysis of Fractures and Microstructures on Different Injection Speeds in High-Pressure Die-Casting Magnesium Alloy
In this study, to clarify the unknown physical properties of the Mg-Al-Th-RE alloy, the relationship between the injection conditions and the internal porosities, and the mechanical properties exerted by the solidification microstructure was investigated. The obtained cast samples were investigated using X-ray CT internal measurements, tensile tests, Vickers hardness tests, and solidification microstructure observations. The tensile strength and the elongation at the injection speed of 5.0 m/s were higher than at 2.0 m/s. The number of porosities affected the tensile strength and the elongation even at the same fracture position. In addition, it was confirmed that segregation affected the destruction smaller the porosity size and the greater the variability of porosity. As the injection speed increased, the amount of heat transferred between the molten metal and the wall surface also increased, resulting in quick freezing and solidification. The tensile strength increased at the injection speed of 5.0 m/s because the interface between the scattered primary crystals and eutectic systems was narrow. On the other hand, at the injection speed of 2.0 m/s, the tensile strength decreased because the molten metal was delayed in solidification and dendrite growth became remarkable
Direct Observation of High-Temperature Polaronic Behavior In Colossal Magnetoresistive Manganites
The temperature dependence of the electronic and atomic structure of the
colossal magnetoresistive oxides (x = 0.3, 0.4) has
been studied using core and valence level photoemission, x-ray absorption and
emission, and extended x-ray absorption fine structure spectroscopy. A dramatic
and reversible change of the electronic structure is observed on crossing the
Curie temperature, including charge localization and spin moment increase of
Mn, together with Jahn-Teller distortions, both signatures of polaron
formation. Our data are also consistent with a phase-separation scenario.Comment: 5 pages, 4 figures, revte
Electron and Neutron Electric Dipole Moments in the Focus Point Scenario of SUGRA Model
We estimate the electron and neutron electric dipole moments in the focus
point scenario of the minimal SUGRA model corresponding to large sfermion
masses and moderate to large . There is a viable region of moderate
fine-tuning in the parameter space, around , where the
experimental limits on these electric dipole moments can be satisfied without
assuming unnaturally small phase angles. But the fine-tuning constraints become
more severe for .Comment: 16 pages, LaTeX, 4 postscript figures. Very minor changes made in
only a few sentences for clarification. Final version to appear in Phys. Rev.
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