1,272 research outputs found
Qualitative and Quantitative Methods in computer Application to Painting: An Art Historical Perspective
Art historical analysis of data collected from field trips have usually been through a qualitative method of analysis. The interpretations of results would often time take judgmental or subjective dimensions. Such analysis and interpretations could allow the reader of such a result to be tempted to suggest their own meanings or interpretations that may subjectively take a fresh perspective. With interdisciplinary researches and collaborations across disciplines, the possibility of benefiting from analytical methods of data analysis is making inroads into Art History. This makes it possible for the quantitative methods of using the Chi square test to arrive at positions and conclusions. The focus of this research was to investigate the application of computer to Painting among painters in Nigeria. Saliu (1994:78) states how the religious and cultural life of the Ebira have been affected, as a result of the coming of Christianity and Islam, and how the influence of Western education changed the socio-political life of the Ebira. In the same vein, Western influence has continued unabated even with the computer. Change in the way artists work is also evident as well as its attendant influence on the painter. This research therefore, embarked on an investigative approach to arrive at the stated objectives. Data was collected from field trips using questionnaires, interviews, observation of painters at work with the computer, art galleries, books, magazines, newspapers, internet, and interviews via email with artists. Research equipment such as digital camera; video camera/recorder were used. In an attempt to study the paintings, a grouping of the works was made and critically analyzed, by considering the formalistic elements, programmes used and characteristics of the programmes. Research design, according to Olaofe (2010:90) is a “blue print for the measurement of variables, collection and analysis of data”. The author goes further to list types of research designs like experimental, action-research, survey, longitudinal, analytical, correlation, descriptive and qualitative. The methodology employed for this investigation was based on art history paradigms which are essentially qualitative. This includes the survey method, descriptive method, and comparative analysis. These methods were adopted by previous researchers including Jari (2007), Wrong (2009), Adogbo and Ojo (2003), Trowel (1994) and Babalola (1981) in Saliu (1994), Evans (1965) and Lewis (2014). Quantitative values in the objectives necessitated the use of questionnaire as an exploratory tool which was statistically analysed
Fluctuations and scaling in creep deformation
The spatial fluctuations of deformation are studied in creep in the Andrade's
power-law and the logarithmic phases, using paper samples. Measurements by the
Digital Image Correlation technique show that the relative strength of the
strain rate fluctuations increases with time, in both creep regimes. In the
Andrade creep phase characterized by a power law decay of the strain rate
, with , the fluctuations obey
, with . The local
deformation follows a data collapse appropriate for an absorbing
state/depinning transition. Similar behavior is found in a crystal plasticity
model, with a jamming or yielding phase transition
Implementation of LS, MMSE and SAGE Channel Estimators for Mobile MIMO-OFDM
The use of decision directed (DD) channel estimation in a multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) downlink receiver is studied in this paper. The 3GPP long term evolution (LTE) based pilot structure is used as a benchmark. The space-alternating
generalized expectation-maximization (SAGE) algorithm is used to improve the performance from that of the pilot symbol based least-squares (LS) channel estimator. The DD channel estimation improves the performance with high user velocities, where the pilot symbol density is not sufficient. Minimum mean square error (MMSE) filtering can also be used in estimating the channel
in between pilot symbols. The DD channel estimation can be used to reduce the pilot overhead without any performance degradation by transmitting data instead of pilot symbols. The pilot overhead is reduced to a third of the LTE pilot overhead, obtaining a ten percent increase in throughput. The pilot based
LS, MMSE and the SAGE channel estimators are implemented and the performance-complexity trade-offs are studied
Targeting Glycogen Synthase Kinase-3β for Therapeutic Benefit against Oxidative Stress in Alzheimer's Disease: Involvement of the Nrf2-ARE Pathway
Specific regions of the Alzheimer's disease (AD) brain are burdened with extracellular protein deposits, the accumulation of which is concomitant with a complex cascade of overlapping events. Many of these pathological processes produce oxidative stress. Under normal conditions, oxidative stress leads to the activation of defensive gene expression that promotes cell survival. At the forefront of defence is the nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor that regulates a broad spectrum of protective genes. Glycogen synthase kinase-3β (GSK-3β) regulates Nrf2, thus making this kinase a potential target for therapeutic intervention aiming to boost the protective activation of Nrf2. This paper aims to review the neuroprotective role of Nrf2 in AD, with special emphasis on the role of GSK-3β in the regulation of the Nrf2 pathway. We also examine the potential of inducing GSK-3β by small-molecule activators, dithiocarbamates, which potentially exert their beneficial therapeutic effects via the activation of the Nrf2 pathway
Help A Sista Out: Black Women Doctoral Students’ Use of Peer Mentorship as an Act of Resistance
Many Black women doctoral students entering and persisting through graduate study lack the affirmation, community, and resources necessary to confidently assert themselves as members of the academy. These barriers make it especially difficult for Black women to effectively navigate doctoral programs that privilege and normalize elite white male experiences. Using Black feminism as the conceptual lens, this manuscript presents a burgeoning peer mentorship framework of Black women doctoral students attending a predominantly white institution through a collective Black feminist autoethnography. This model highlights our strategy for not only surviving the academy, but also resisting manifestations of white heteropatriarchal violence within academia. In contrast to more common and formal faculty-student mentorship models, we engage an emergent, horizontal peer mentorship framework, comprised of three tenets: radical coping, communal sista scholarship, and the cultivation of an authentic holistic self
The nuclear to host galaxy relation of high redshift quasars
We present near-infrared imaging with ESO VLT+ISAAC of the host galaxies of
low luminosity quasars in the redshift range 1 < z < 2, aimed at investigating
the relationship between the nuclear and host galaxy luminosities at high
redshift. This work complements our previous study to trace the cosmological
evolution of the host galaxies of high luminosity quasars (Falomo et al. 2004).
The new sample includes 15 low luminosity quasars, nine radio-loud (RLQ) and
six radio-quiet (RQQ). They have similar distribution of redshift and optical
luminosity, and together with the high luminosity quasars they cover a large
range (~4 mag) of the quasar luminosity function. The host galaxies of both
types of quasars are in the range of massive inactive ellipticals between L*
and 10 L*. RLQ hosts are systematically more luminous than RQQ hosts by a
factor of ~2. This difference is similar to that found for the high luminosity
quasars. This luminosity gap appears to be independent of the rest-frame U-band
luminosity but clearly correlated with the rest-frame R-band luminosity. The
color difference between the RQQs and the RLQs is likely a combination of an
intrinsic difference in the strength of the thermal and nonthermal components
in the SEDs of RLQs and RQQs, and a selection effect due to internal dust
extinction. For the combined set of quasars, we find a reasonable correlation
between the nuclear and the host luminosities. This correlation is less
apparent for RQQs than for RLQs. If the R-band luminosity is representative of
the bolometric luminosity, and assuming that the host luminosity is
proportional to the black hole mass, as observed in nearby massive spheroids,
quasars emit with a relatively narrow range of power with respect to their
Eddington luminosity and with the same distribution for RLQs and RQQs.Comment: Accepted for publication in ApJ, 24 pages, 4 figure
Multiscale Analysis of Spreading in a Large Communication Network
In temporal networks, both the topology of the underlying network and the
timings of interaction events can be crucial in determining how some dynamic
process mediated by the network unfolds. We have explored the limiting case of
the speed of spreading in the SI model, set up such that an event between an
infectious and susceptible individual always transmits the infection. The speed
of this process sets an upper bound for the speed of any dynamic process that
is mediated through the interaction events of the network. With the help of
temporal networks derived from large scale time-stamped data on mobile phone
calls, we extend earlier results that point out the slowing-down effects of
burstiness and temporal inhomogeneities. In such networks, links are not
permanently active, but dynamic processes are mediated by recurrent events
taking place on the links at specific points in time. We perform a multi-scale
analysis and pinpoint the importance of the timings of event sequences on
individual links, their correlations with neighboring sequences, and the
temporal pathways taken by the network-scale spreading process. This is
achieved by studying empirically and analytically different characteristic
relay times of links, relevant to the respective scales, and a set of temporal
reference models that allow for removing selected time-domain correlations one
by one
Fibrillation in patients subjected to coronary artery bypass grafting
AbstractObjectiveAtrial fibrillation is the most frequently encountered postoperative arrhythmic complication after coronary artery bypass grafting. Ischemic preconditioning has proved a potent endogenous factor in suppressing ischemia-reperfusion–induced arrhythmias. The protective effect of ischemic preconditioning on atrial fibrillation after coronary artery bypass grafting has not been studied. The purpose of the present study was to investigate whether ischemic preconditioning had an effect on postoperative atrial fibrillation in patients undergoing coronary artery bypass grafting.MethodsEighty-five patients undergoing coronary artery bypass grafting were randomized into ischemic preconditioning and control groups. Holter data from 24-hour electrocardiography were collected 1 day before the operation to the second postoperative day. Atrial fibrillation was registered as positive if any atrial fibrillation event occurred.ResultsThe overall incidence of postoperative atrial fibrillation and sustained atrial fibrillation was 34.1% and 27.1%, respectively. The occurrence of atrial fibrillation was significantly lower in the ischemic preconditioning group (21.4% in patients undergoing ischemic preconditioning and 46.5% in control subjects, P = .015). Preoperative recent unstable angina did not influence the incidence of atrial fibrillation. Patients with atrial fibrillation had longer intensive care unit stays and compromised postoperative hemodynamic outcomes. Binary logistic regression analysis showed that ischemic preconditioning, preoperative mean heart rate, and postoperative pulmonary capillary wedge pressure were the independent predictors of atrial fibrillation.ConclusionsPostcoronary artery bypass grafting atrial fibrillation is associated with more complicated postoperative outcome. Higher preoperative heart rate and postoperative pulmonary capillary wedge pressure were the independent predictors of atrial fibrillation. Recent unstable angina is not related to the occurrence of postcoronary artery bypass grafting atrial fibrillation. Ischemic preconditioning significantly suppresses postcoronary artery bypass grafting atrial fibrillation, suggesting that ischemic preconditioning can be used as an effective prophylactic method for postoperative atrial fibrillation
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