1,395 research outputs found
Dr. Eugene Grigsby\u27s Connections to Art, African American Life in the South, and Social Justice Education: Implications for Art Education Curriculum
DR. EUGENE GRIGSBY’S CONNECTIONS TO ART, AFRICAN AMERICAN LIFE IN THE SOUTH, AND SOCIAL JUSTICE EDUCATION: IMPLICATIONS FOR ART EDUCATION CURRICULUM by REGINALD STEPHENS (Under the Direction of Dr. Sabrina Ross) ABSTRACT Building on concepts of double consciousness (Dubois, 1903/1994), the negative effects of a lack of visibility in curricula (Woodson, 2010), critical race theory, and the notion that artists’ lived experiences of oppression encourage actions and art that challenge injustice (Bey, 2011), this study sought to demonstrate that the lives and works of Black artists from the South in the early 20th Century are pedagogical. Inspired by the critical race methodology of counter storytelling (Solorzano & Yosso, 2002), the life and works of 20th Century Black artists, with special emphasis on the life and work of Dr. Eugene Grigsby, were examined within the socio historical context of the U.S. South. Through a critical aesthetic analysis of the life histories and artwork of Dr. Eugene Grigsby and other Black artists, this study sought to illuminate the informal curriculum of social justice (i.e., the ways in which the everyday lived experiences of Black Southern artists taught lessons on how to challenge racism and other structures of oppression) evident in the life and work products of each artist. By making connections between the life and work of Black artists and issues of social justice, this study sought to demonstrate that infusing art curricula with information on the lives and works of Black artists holds potential for enriching art curriculum in U.S. public schools and altering the miseducation of public school students who suffer as a result of a lack of Black visibility in the curriculum. INDEX WORDS: Black artists; art education; curriculum studies; Eugene Grigsby; social justice; double consciousness; counter-storytelling
Determinants of the voltage dependence of G protein modulation within calcium channel β subunits
CaVβ subunits of voltage-gated calcium channels contain two conserved domains, a src-homology-3 (SH3) domain and a guanylate kinase-like (GK) domain with an intervening HOOK domain. We have shown in a previous study that, although Gβγ-mediated inhibitory modulation of CaV2.2 channels did not require the interaction of a CaVβ subunit with the CaVα1 subunit, when such interaction was prevented by a mutation in the α1 subunit, G protein modulation could not be removed by a large depolarization and showed voltage-independent properties (Leroy et al., J Neurosci 25:6984–6996, 2005). In this study, we have investigated the ability of mutant and truncated CaVβ subunits to support voltage-dependent G protein modulation in order to determine the minimal domain of the CaVβ subunit that is required for this process. We have coexpressed the CaVβ subunit constructs with CaV2.2 and α2δ-2, studied modulation by the activation of the dopamine D2 receptor, and also examined basal tonic modulation. Our main finding is that the CaVβ subunit GK domains, from either β1b or β2, are sufficient to restore voltage dependence to G protein modulation. We also found that the removal of the variable HOOK region from β2a promotes tonic voltage-dependent G protein modulation. We propose that the absence of the HOOK region enhances Gβγ binding affinity, leading to greater tonic modulation by basal levels of Gβγ. This tonic modulation requires the presence of an SH3 domain, as tonic modulation is not supported by any of the CaVβ subunit GK domains alone
Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling
This paper investigates the dependence of synchronization transitions of
bursting oscillations on the information transmission delay over scale-free
neuronal networks with attractive and repulsive coupling. It is shown that for
both types of coupling, the delay always plays a subtle role in either
promoting or impairing synchronization. In particular, depending on the
inherent oscillation period of individual neurons, regions of irregular and
regular propagating excitatory fronts appear intermittently as the delay
increases. These delay-induced synchronization transitions are manifested as
well-expressed minima in the measure for spatiotemporal synchrony. For
attractive coupling, the minima appear at every integer multiple of the average
oscillation period, while for the repulsive coupling, they appear at every odd
multiple of the half of the average oscillation period. The obtained results
are robust to the variations of the dynamics of individual neurons, the system
size, and the neuronal firing type. Hence, they can be used to characterize
attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related
work available at http://arxiv.org/abs/0907.4961 and
http://www.matjazperc.com/
Host Suitability of a Gregarious Parasitoid on Beetle Hosts: Flexibility between Fitness of Adult and Offspring
Behavioral tactics play a crucial role in the evolution of species and are likely to be found in host-parasitoid interactions where host quality may differ between host developmental stages. We investigated foraging decisions, parasitism and related fitness in a gregarious ectoparasitoid, Sclerodermus harmandi in relation to two distinct host developmental stages: larvae and pupae. Two colonies of parasitoids were reared on larvae of Monochamus alternatus and Saperda populnea (Cerambycidae: Lamiinae). Paired-choice and non-choice experiments were used to evaluate the preference and performance of S. harmandi on larvae and pupae of the two species. Foraging decisions and offspring fitness-related consequences of S. harmandi led to the selection of the most profitable host stage for parasitoid development. Adult females from the two colonies oviposited more quickly on pupae as compared to larvae of M. alternatus. Subsequently, their offspring development time was faster and they gained higher body weight on the pupal hosts. This study demonstrates optimal foraging of intraspecific détente that can occur during host-parasitoid interactions, of which the quality of the parasitism (highest fitness benefit and profitability) is related to the host developmental stage utilized. We conclude that S. harmandi is able to perfectly discriminate among host species or stages in a manner that maximizes its offspring fitness. The results indicated that foraging potential of adults may not be driven by its maternal effects, also induced flexibly with encountering prior host quality
Multiple Local and Recent Founder Effects of TGM1 in Spanish Families
<div><h3>Background</h3><p>Mutations in the <em>TGM1</em> gene encoding transglutaminase 1 are a major cause of autosomal recessive congenital ichthyosis. In the Galician (NW Spain) population, three mutations, c.2278C>T, c.1223_1227delACAC and c.984+1G>A, were observed at high frequency, representing ∼46%, ∼21% and ∼13% of all <em>TGM1</em> gene mutations, respectively. Moreover, these mutations were reported only once outside of Galicia, pointing to the existence of historical episodes of local severe genetic drift in this region.</p> <h3>Methodology/Principal Findings</h3><p>In order to determine whether these mutations were inherited from a common ancestor in the Galician population, and to estimate the number of generations since their initial appearance, we carried out a haplotype-based analysis by way of genotyping 21 SNPs within and flanking the <em>TGM1</em> gene and 10 flanking polymorphic microsatellite markers spanning a region of 12 Mb. Two linkage disequilibrium based methods were used to estimate the time to the most recent common ancestor (TMRCA), while a Bayesian-based procedure was used to estimate the age of the two mutations. Haplotype reconstruction from unphased genotypes of all members of the affected pedigrees indicated that all carriers for each of the two mutations harbored the same haplotypes, indicating common ancestry.</p> <h3>Conclusions/Significance</h3><p>In good agreement with the documentation record and the census, both mutations arose between 2,800–2,900 years ago (y.a.), but their TMRCA was in the range 600–1,290 y.a., pointing to the existence of historical bottlenecks in the region followed by population growth. This demographic scenario finds further support on a Bayesian Coalescent Analysis based on <em>TGM1</em> haplotypes that allowed estimating the occurrence of a dramatic reduction of effective population size around 900–4,500 y.a. (95% highest posterior density) followed by exponential growth.</p> </div
Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males
Detecting failure of climate predictions
The practical consequences of climate change challenge society to formulate responses that are more suited to achieving long-term objectives, even if those responses have to be made in the face of uncertainty. Such a decision-analytic focus uses the products of climate science as probabilistic predictions about the effects of management policies. Here we present methods to detect when climate predictions are failing to capture the system dynamics. For a single model, we measure goodness of fit based on the empirical distribution function, and define failure when the distribution of observed values significantly diverges from the modelled distribution. For a set of models, the same statistic can be used to provide relative weights for the individual models, and we define failure when there is no linear weighting of the ensemble models that produces a satisfactory match to the observations. Early detection of failure of a set of predictions is important for improving model predictions and the decisions based on them. We show that these methods would have detected a range shift in northern pintail 20 years before it was actually discovered, and are increasingly giving more weight to those climate models that forecast a September ice-free Arctic by 2055
Short-Lived IFN-γ Effector Responses, but Long-Lived IL-10 Memory Responses, to Malaria in an Area of Low Malaria Endemicity
Immunity to malaria is widely believed to wane in the absence of reinfection, but direct evidence for the presence or absence of durable immunological memory to malaria is limited. Here, we analysed malaria-specific CD4+ T cell responses of individuals living in an area of low malaria transmission in northern Thailand, who had had a documented clinical attack of P. falciparum and/or P. vivax in the past 6 years. CD4+ T cell effector memory (CD45RO+) IFN-γ (24 hours ex vivo restimulation) and cultured IL-10 (6 day secretion into culture supernatant) responses to malaria schizont antigens were detected only in malaria-exposed subjects and were more prominent in subjects with long-lived antibodies or memory B cells specific to malaria antigens. The number of IFN-γ-producing effector memory T cells declined significantly over the 12 months of the study, and with time since last documented malaria infection, with an estimated half life of the response of 3.3 (95% CI 1.9–10.3) years. In sharp contrast, IL-10 responses were sustained for many years after last known malaria infection with no significant decline over at least 6 years. The observations have clear implications for understanding the immunoepidemiology of naturally acquired malaria infections and for malaria vaccine development
GITR signaling potentiates airway hyperresponsiveness by enhancing Th2 cell activity in a mouse model of asthma
<p>Abstract</p> <p>Background</p> <p>Allergic asthma is characterized by airway hyperresponsiveness (AHR) and allergic inflammation of the airways, driven by allergen-specific Th2 cells. The asthma phenotypes and especially AHR are sensitive to the presence and activity of regulatory T (Treg) cells in the lung. Glucocorticoid-induced tumor necrosis factor receptor (GITR) is known to have a co-stimulatory function on effector CD4<sup>+ </sup>T cells, rendering these cells insensitive to Treg suppression. However, the effects of GITR signaling on polarized Th1 and Th2 cell effector functions are not well-established. We sought to evaluate the effect of GITR signaling on fully differentiated Th1 and Th2 cells and to determine the effects of GITR activation at the time of allergen provocation on AHR and airway inflammation in a Th2-driven mouse model of asthma.</p> <p>Methods</p> <p>CD4<sup>+</sup>CD25<sup>- </sup>cells were polarized <it>in vitro </it>into Th1 and Th2 effector cells, and re-stimulated in the presence of GITR agonistic antibodies to assess the effect on IFNγ and IL-4 production. To evaluate the effects of GITR stimulation on AHR and allergic inflammation in a mouse asthma model, BALB/c mice were sensitized to OVA followed by airway challenges in the presence or absence of GITR agonist antibodies.</p> <p>Results</p> <p>GITR engagement potentiated cytokine release from CD3/CD28-stimulated Th2 but not Th1 cells <it>in vitro</it>. In the mouse asthma model, GITR triggering at the time of challenge induced enhanced airway hyperresponsiveness, serum IgE and <it>ex vivo </it>Th2 cytokine release, but did not increase BAL eosinophilia.</p> <p>Conclusion</p> <p>GITR exerts a differential effect on cytokine release of fully differentiated Th1 and Th2 cells <it>in vitro</it>, potentiating Th2 but not Th1 cytokine production. This effect on Th2 effector functions was also observed <it>in vivo </it>in our mouse model of asthma, resulting in enhanced AHR, serum IgE responses and Th2 cytokine production. This is the first report showing the effects of GITR activation on cytokine production by polarized primary Th1 and Th2 populations and the relevance of this pathway for AHR in mouse models for asthma. Our data provides crucial information on the mode of action of the GITR signaling, a pathway which is currently being considered for therapeutic intervention.</p
Predictors of gastrointestinal lesions on endoscopy in iron deficiency anemia without gastrointestinal symptoms
<p>Abstract</p> <p>Background</p> <p>Iron deficiency anaemia (IDA) due to occult gastrointestinal (GI) blood loss usually remains unnoticed until patient become symptomatic. There is sparse data in IDA patients without gastrointestinal symptoms. This study was designed to find out the frequency and predictors of endoscopic lesions in IDA without gastrointestinal symptoms. Cross-sectional study performed on a convenience sample of consecutive subjects.</p> <p>Methods</p> <p>Ninety five consecutive patients with laboratory based diagnosis of IDA having no gastrointestinal symptoms were interviewed and their clinical and biochemical variables were recorded. All the study patients underwent esophago-gastroduodenoscopy (EGD) and colonoscopy. Endoscopic findings were documented as presence/absence of bleeding related lesion and presence/absence of cause of IDA. Multiple logistic regressions were performed to identify variables significantly related to outcome variables.</p> <p>Results</p> <p>Possible cause of anaemia was found in 71% and bleeding related lesions were found in 53% of patients. Upper gastrointestinal tract lesions were found in 41% of patients with bleeding related lesions. On multivariable logistic regression; advancing age, low mean corpuscular volume (MCV ≤ 60 fl), and positive fecal occult blood test were predictive factors for bleeding related GI lesions and cause of IDA</p> <p>Conclusion</p> <p>Clinical and Biochemical markers can predict gastrointestinal lesions on endoscopy in IDA patients without gastrointestinal symptoms. High proportion of upper gastrointestinal involvement warrants EGD as initial endoscopic procedure however, this needs validation by further studies.</p
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