877 research outputs found
South-to-South dialogues between Brazilian and Kenyan artivists: decolonial and intersectional feminist perspectives
In this article, we analyze experiences in which Brazilian and Kenyan artivists (artists who are activists) used animation to challenge colonial hierarchies that devalue Global Southern knowledges, histories, and stories. We draw from ethnographic observations, in-depth interviews, and artivistsâ experiences in two animation workshops: (a) Portrait of Marielle, produced with Kenyan artivists in Nairobi; (b) Homage to WangarÄ© Maathai, produced with Brazilian artivists in Salvador. We ask: how can artivist creative practices be used as tools for global movement building, contesting the colonial legacy of fragmented relationships between Global South peoples? We evoke decolonial and standpoint intersectional feminist perspectives to propose an understanding of artivism that considers the specificities of Global South contexts, connecting it to two axes: (a) establishing dialogical spaces and (b) mobilizing memories and histories. Our understanding of South-to-South artivist dialogues results from the ways in which notions of âpluriversality,â âincompletenessâ and âhumility,â which stem from Latin American and African scholarship are intertwined. When marginalized groups exchange âsituated knowledgesâ and express themselves through artivism from âintersectional standpointsâ or âlugares de fala,â this can have a binding nature, creating transformative connections between Global South peoples
South-to-South dialogues between Brazilian and Kenyan artivists: decolonial and intersectional feminist perspectives
In this article, we analyze experiences in which Brazilian and Kenyan artivists (artists who are activists) used animation to challenge colonial hierarchies that devalue Global Southern knowledges, histories, and stories. We draw from ethnographic observations, in-depth interviews, and artivistsâ experiences in two animation workshops: (a) Portrait of Marielle, produced with Kenyan artivists in Nairobi; (b) Homage to WangarÄ© Maathai, produced with Brazilian artivists in Salvador. We ask: how can artivist creative practices be used as tools for global movement building, contesting the colonial legacy of fragmented relationships between Global South peoples? We evoke decolonial and standpoint intersectional feminist perspectives to propose an understanding of artivism that considers the specificities of Global South contexts, connecting it to two axes: (a) establishing dialogical spaces and (b) mobilizing memories and histories. Our understanding of South-to-South artivist dialogues results from the ways in which notions of âpluriversality,â âincompletenessâ and âhumility,â which stem from Latin American and African scholarship are intertwined. When marginalized groups exchange âsituated knowledgesâ and express themselves through artivism from âintersectional standpointsâ or âlugares de fala,â this can have a binding nature, creating transformative connections between Global South peoples
Two-to-one resonant multi-modal dynamics of horizontal/inclined cables. Part I : theoretical formulation and model validation
This paper is first of the two papers dealingwith analytical investigation of resonant multimodal dynamics due to 2:1 internal resonances in the finite-amplitude free vibrations of horizontal/inclined cables. Part I deals with theoretical formulation and validation of the general cable model. Approximate nonlinear partial differential equations of 3-D coupled motion of small sagged cables - which account for both spatio-temporal variation of nonlinear dynamic tension and system asymmetry due to inclined sagged configurations - are presented. A multidimensional Galerkin expansion of the solution ofnonplanar/planar motion is performed, yielding a complete set of system quadratic/cubic coefficients. With the aim of parametrically studying the behavior of horizontal/inclined cables in Part II [25], a second-order asymptotic analysis under planar 2:1 resonance is accomplished by the method of multiple scales. On accounting for higher-order effectsof quadratic/cubic nonlinearities, approximate closed form solutions of nonlinear amplitudes, frequencies and dynamic configurations of resonant nonlinear normal modes reveal the dependence of cable response on resonant/nonresonant modal contributions. Depending on simplifying kinematic modeling and assigned system parameters, approximate horizontal/inclined cable models are thoroughly validated by numerically evaluating statics and non-planar/planar linear/non-linear dynamics against those of the exact model. Moreover, the modal coupling role and contribution of system longitudinal dynamics are discussed for horizontal cables, showing some meaningful effects due to kinematic condensation
Metastatic tumors to the stomach: clinical and endoscopic features.
AIM: To evaluate the clinical and endoscopic patterns in a large series of patients with metastatic tumors in the stomach. METHODS: A total of 64 patients with gastric metastases from solid malignant tumors were retrospectively examined between 1990 and 2005. The clinicopathological findings were reviewed along with tumor characteristics such as endoscopic pattern, location, size and origin of the primary sites. RESULTS: Common indications for endoscopy were anemia, bleeding and epigastric pain. Metastases presented as solitary (62.5%) or multiple (37.5%) tumors were mainly located in the middle or upper third of stomach. The main primary metastatic tumors were from breast and lung cancer and malignant melanoma. CONCLUSION: As the prognosis of cancer patients has been improving gradually, gastrointestinal (GI) metastases will be encountered more often. Endoscopic examinations should be conducted carefully in patients with malignancies, and endoscopic biopsies and information on the patient's clinical history are useful for correct diagnosis of gastric metastases
Investigation of Endogenous Chemical Exchange Saturation Transfer Effects with Magnetic Resonance Imaging in Various Animal Models of Neurological Disorders
Chemical Exchange Saturation Transfer (CEST), is an emerging Magnetic Resonance Imaging (MRI) technique. CEST indirectly measures exchangeable protons contained in either endogenous or exogenous compounds by measuring the water signal reduction due to magnetisation exchange between these compounds and the surrounding water. CEST offers sensitivity enhancement compared to any method which directly measures these compounds. The complexity of the CEST signal in-vivo limits direct quantitative interpretation. However, the technique is inherently sensitive to a range of physiological parameters, such as temperature, pH and metabolite concentration. In order to investigate the relative importance of these different contributing factors, the work described in this thesis used the Bloch-McConnell equation system to model the CEST effect, for CEST sequence optimisation and data interpretation. Bovine Serum Albumin (BSA) phantoms were scanned with a CEST sequence and the results were compared to standard contrast methods (T1, T2). The CEST effects were correlated with changes in environmental pH, temperature and metabolite concentration. Next, a spectroscopic CEST sequence was implemented for spinal cord CEST and two models of neurodegenerative diseases were investigated. First, a model of Amyotrophic Lateral Sclerosis (ALS), revealed no changes in the CEST signal over the time course of the disease; the finding matched post-mortem soluble protein concentration analysis. Second, a model of Spinal and Bulbar Muscular Atrophy (SBMA), revealed no changes in the CEST signal of affected mice scanned at 10 and 12 months of age. However, changes in the CEST signal were observed in control mice and this again agreed with post-mortem protein concentration analysis. Finally, the potential for CEST to measure regional pH changes in a piglet model of Hypoxic Ischemia (HI) was investigated. CEST data were compared and found to agree with 31P MRS, measuring intracellular pH (pHi) and 1H MRS, measuring cerebral lactate levels
Penggunaan Air Kelapa untuk Setek Batang Jati (Tectona Grandis)
Teak plant wasa treewhich timber has durability classI and strong class I. It hasmany benefits, from roots to leaves. Variousbenefits of teak causing to do cultivation, one of propagation activities that often carried out was vegetative. Vegetative propagation of plants can be done bystem cutting, root cutting and shoot cutting. Using of growth regulator with coconut water immersion is expected to spur the growth rootofteak stem cutting. This study aimed to determine the effect of using coconut water to increase the success of teak stem cuttinggrowth, andto determine the best dose of using coconut water forteak stem cutting growth. This treatment used Completely Randomized Design(CRD). This research consisted of five treatments that usedcoconut water treatment 0%, 25%, 50%, 75%, and 100%. Each treatmentconsisted of five teak stem cuttings with repetition as much as 5 times. Amount ofmaterial plants required 5 x 5 x 5 = 125 teak stem cuttings. The resultshowed by using coconut wateras a growth regulator could increasethe growth of teak (Tectona grandis) stem cuttingin 50%--100% concentration and the best dose of coconut water asa growth regulator was 100%
Pulsive feedback control for stabilizing unstable periodic orbits in a nonlinear oscillator with a non-symmetric potential
We examine a strange chaotic attractor and its unstable periodic orbits in
case of one degree of freedom nonlinear oscillator with non symmetric
potential. We propose an efficient method of chaos control stabilizing these
orbits by a pulsive feedback technique. Discrete set of pulses enable us to
transfer the system from one periodic state to another.Comment: 11 pages, 4 figure
Separation of quadrupolar and magnetic contributions to spin-lattice relaxation in the case of a single isotope
We present a NMR pulse double-irradiation method which allows one to separate
magnetic from quadrupolar contributions in the spin-lattice relaxation. The
pulse sequence fully saturates one transition while another is observed. In the
presence of a Delta m = 2 quadrupolar contribution, the intensity of the
observed line is altered compared to a standard spin-echo experiment. We
calculated analytically this intensity change for spins I=1, 3/2, 5/2, thus
providing a quantitative analysis of the experimental results. Since the pulse
sequence we used takes care of the absorbed radio-frequency power, no problems
due to heating arise. The method is especially suited when only one NMR
sensitive isotope is available. Different cross-checks were performed to prove
the reliability of the obtained results. The applicability of this method is
demonstrated by a study of the plane oxygen 17O (I = 5/2) in the
high-temperature superconductor YBa_2Cu_4O_8: the 17O spin-lattice relaxation
rate consists of magnetic as well as quadrupolar contributions.Comment: 7 pages, 6 figure
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