266 research outputs found
Brain Mass and Encephalization Quotients in the Domestic Industrial Pig (Sus scrofa)
open6siIn the present study we examined the brain of fetal, newborn, and adult pigs raised for meat production. The fresh and formalin-fixed weights of the brain have been recorded and used, together with body weight, to calculate the Encephalization Quotient (EQ). The weight of the cerebellum has been used to calculate the Cerebellar Quotient (CQ). The results have been discussed together with analogue data obtained in other terrestrial Cetartiodactyla (including the domestic bovine, sheep, goat, and camel), domesticated Carnivora, Proboscidata, and Primates. Our study, based on a relatively large experimental series, corrects former observations present in the literature based on smaller samples, and emphasizes that the domestic pig has a small brain relative to its body size (EQ = 0.38 for adults), possibly due to factors linked to the necessity of meat production and improved body weight. Comparison with other terrestrial Cetartiodactyla indicates a similar trend for all domesticated species.openMinervini, Serena; Accogli, Gianluca; Pirone, Andrea; Graïc, Jean-Marie; Cozzi, Bruno; Desantis, SalvatoreMinervini, Serena; Accogli, Gianluca; Pirone, Andrea; Graic, JEAN-MARIE; Cozzi, Bruno; Desantis, Salvator
Using Students’ Contextual Frameworks to Provide Equitable Education through the New Literacy Studies, Social Justice Education, and Intentional Practices
Within the past decade and a half, education policies in the United States have become more standards-based and thus more restrictive. No Child Left Behind, under President Bush’s administration, began placing heavy weight on tests to measure student achievement (Klein, 2015); the Common Core State Standards Initiative, under President Obama’s administration, continued the curriculum standardization and increased connections to performance evaluations of teachers (Gewertz, 2015). The standardization that currently characterizes American schools poses several issues for students, especially those on the margins of society—socially, culturally, and economically. Classroom culture, especially under the standardization movement, is culturally biased and leaves few opportunities for traditionally marginalized students to feel at home and welcomed (Irvine, 2003, p. 6). Further, the different high-stakes tests mandated by current education policies take student individuality out of education and overlook marginalized students, as the information and testing practices reflect nothing of their own cultures (McCleskey, 2014). Similarly, despite policymakers’ communicated intentions to create equal learning experiences for all students, their plans are failing because they are relying on equality rather than equity (Irvine, 2003). Lastly, instructional methods, specifically as they are used with marginalized students, reveal color-blindness that, despite teachers’ intentions, are harming our students rather than empowering them (Garces, 2016)
Connections between the Niagara Movement, the N.A.A.C.P., and Alonzo Herndon’s Atlanta Life Insurance Company for The Purpose of The Long Civil Rights Movement
Precursor Processes of Human Self-Initiated Action
A gradual buildup of electrical potential over motor areas precedes self-initiated movements. Recently, such “readiness potentials” (RPs) were attributed to stochastic fluctuations in neural activity. We developed a new experimental paradigm that operationalized self-initiated actions as endogenous ‘skip’ responses while waiting for target stimuli in a perceptual decision task. We compared these to a block of trials where participants could not choose when to skip, but were instead instructed to skip. Frequency and timing of motor action were therefore balanced across blocks, so that conditions differed only in how the timing of skip decisions was generated. We reasoned that across-trial variability of EEG could carry as much information about the source of skip decisions as the mean RP. EEG variability decreased more markedly prior to self-initiated compared to externally-triggered skip actions. This convergence suggests a consistent preparatory process prior to self-initiated action. A leaky stochastic accumulator model could reproduce this convergence given the additional assumption of a systematic decrease in input noise prior to self-initiated actions. Our results may provide a novel neurophysiological perspective on the topical debate regarding whether self-initiated actions arise from a deterministic neurocognitive process, or from neural stochasticity. We suggest that the key precursor of self-initiated action may manifest as a reduction in neural noise
The Test- Retest Reliability and Minimal Detectable Change of the Sensory Organization Test and Head- Shake Sensory Organization Test
Context: The assessment of balance deficits following sport- related concussion can be accomplished using computerized dynamic posturography (CDP) testing procedures, including the Sensory Organization Test (SOT) and the Head- Shake Sensory Organization Test (HS- SOT). Although these tests are considered to be important post- concussion balance assessments, the test- retest reliability of the HS- SOT has not been evaluated in a healthy, athletic population. Objective: Our purpose was to evaluate the test- retest reliability of the HS-SOT in a non-concussed, athletic sample. Design: A prospective, time series, cohort design was used. Setting: University research laboratory. Participants or Other Participants: Twenty (8 F, 12 M) healthy intercollegiate athletes (age 19.95 ± 1.28 years, height 175.55 ± 13.57 cm, weight 74.73 ± 17.59 kg). Interventions: Postural stability was assessed at two time intervals (9 days apart). Subjects completed all 6 testing conditions of the SOT and the 2 testing conditions for the HS- SOT. Results: Excellent test- retest reliability was demonstrated for the SOT composite equilibrium scores (ICC 1,1= .83). Moderate test- retest reliability was observed for the SOT equilibrium scores for conditions 2 (.66) and 5 (.65); somatic (.58), visual (.65), and vestibular sensory analyses (.68); and sensory analysis preference (.66). Moderate reliability was also noted for equilibrium scores on condition 5 for the HS- SOT (.65). The test- retest reliability was poor for the HS- SOT equilibrium scores on condition 2 (ICC= .26, δ2= .14), HS-SOT equilibrium score ratio for fixed surface (ICC= .37, δ2 2= .003). Conclusions: Determining the minimal difference in HS- SOT scores (ICC and MDC) representing significant change over time will help clinicians to identify athletes with balance disorders in the acute post- concussion phase
Believing and Perceiving: Authorship Belief Modulates Sensory Attenuation
Sensory attenuation refers to the observation that self-generated stimuli are attenuated, both in terms of their phenomenology and their cortical response compared to the same stimuli when generated externally. Accordingly, it has been assumed that sensory attenuation might help individuals to determine whether a sensory event was caused by themselves or not. In the present study, we investigated whether this dependency is reciprocal, namely whether sensory attenuation is modulated by prior beliefs of authorship. Participants had to judge the loudness of auditory effects that they believed were either self-generated or triggered by another person. However, in reality, the sounds were always triggered by the participants' actions. Participants perceived the tones' loudness attenuated when they believed that the sounds were self-generated compared to when they believed that they were generated by another person. Sensory attenuation is considered to contribute to the emergence of people's belief of authorship. Our results suggest that sensory attenuation is also a consequence of prior belief about the causal link between an action and a sensory change in the environment
Recommended from our members
The prediction of visual stimuli influences auditory loudness discrimination
The brain combines information from different senses to improve performance on perceptual tasks. For instance, auditory processing is enhanced by the mere fact that a visual input is processed simultaneously. However, the sensory processing of one modality is itself subject to diverse influences. Namely, perceptual processing depends on the degree to which a stimulus is predicted. The present study investigated the extent to which the influence of one processing pathway on another pathway depends on whether or not the stimulation in this pathway is predicted. We used an action–effect paradigm to vary the match between incoming and predicted visual stimulation. Participants triggered a bimodal stimulus composed of a Gabor and a tone. The Gabor was either congruent or incongruent compared to an action–effect association that participants learned in an acquisition phase.We tested the influence of action–effect congruency on the loudness perception of the tone. We observed that an incongruent–task-irrelevant Gabor stimulus increases participant’s sensitivity to loudness discrimination. An identical result was obtained for a second condition in which the visual stimulus was predicted by a cue instead of an action. Our results suggest that prediction error is a driving factor of the crossmodal interplay between vision and audition
Associations between infant fungal and bacterial dysbiosis and childhood atopic wheeze in a nonindustrialized setting.
BACKGROUND: Asthma is the most prevalent chronic disease of childhood. Recently, we identified a critical window early in the life of both mice and Canadian infants during which gut microbial changes (dysbiosis) affect asthma development. Given geographic differences in human gut microbiota worldwide, we studied the effects of gut microbial dysbiosis on atopic wheeze in a population living in a distinct developing world environment. OBJECTIVE: We sought to determine whether microbial alterations in early infancy are associated with the development of atopic wheeze in a nonindustrialized setting. METHODS: We conducted a case-control study nested within a birth cohort from rural Ecuador in which we identified 27 children with atopic wheeze and 70 healthy control subjects at 5 years of age. We analyzed bacterial and eukaryotic gut microbiota in stool samples collected at 3 months of age using 16S and 18S sequencing. Bacterial metagenomes were predicted from 16S rRNA data by using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States and categorized by function with Kyoto Encyclopedia of Genes and Genomes ontology. Concentrations of fecal short-chain fatty acids were determined by using gas chromatography. RESULTS: As previously observed in Canadian infants, microbial dysbiosis at 3 months of age was associated with later development of atopic wheeze. However, the dysbiosis in Ecuadorian babies involved different bacterial taxa, was more pronounced, and also involved several fungal taxa. Predicted metagenomic analysis emphasized significant dysbiosis-associated differences in genes involved in carbohydrate and taurine metabolism. Levels of the fecal short-chain fatty acids acetate and caproate were reduced and increased, respectively, in the 3-month stool samples of children who went on to have atopic wheeze. CONCLUSIONS: Our findings support the importance of fungal and bacterial microbiota during the first 100 days of life on the development of atopic wheeze and provide additional support for considering modulation of the gut microbiome as a primary asthma prevention strategy
The sense of agency as tracking control
Does sense of agency (SoA) arise merely from action-outcome associations, or does an additional real-time process track each step along the chain? Tracking control predicts that deviant intermediate steps between action and outcome should reduce SoA. In two experiments, participants learned mappings between two finger actions and two tones. In later test blocks, actions triggered a robot hand moving either the same or a different finger, and also triggered tones, which were congruent or incongruent with the mapping. The perceived delay between actions and tones gave a proxy measure for SoA. Action-tone binding was stronger for congruent than incongruent tones, but only when the robot movement was also congruent. Congruent tones also had reduced N amplitudes, but again only when the robot movement was congruent.We suggest that SoA partly depends on a real time tracking control mechanism, since deviant intermediate action of the robot reduced SoA over the tone
1,2,4-Triazolo[1,5-a]pyrimidines as a Novel Class of Inhibitors of the HIV-1 Reverse Transcriptase-Associated Ribonuclease H Activity
Despite great efforts have been made in the prevention and therapy of human immunodeficiency virus (HIV-1) infection, however the difficulty to eradicate latent viral reservoirs together with the emergence of multi-drug-resistant strains require the search for innovative agents, possibly exploiting novel mechanisms of action. In this context, the HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H), which is one of the few HIV-1 encoded enzymatic function still not targeted by any current drug, can be considered as an appealing target. In this work, we repurposed in-house anti-influenza derivatives based on the 1,2,4-triazolo[1,5-a]-pyrimidine (TZP) scaffold for their ability to inhibit HIV-1 RNase H function. Based on the results, a successive multi-step structural exploration around the TZP core was performed leading to identify catechol derivatives that inhibited RNase H in the low micromolar range without showing RT-associated polymerase inhibitory activity. The antiviral evaluation of the compounds in the MT4 cells showed any activity against HIV-1 (IIIB strain). Molecular modelling and mutagenesis analysis suggested key interactions with an unexplored allosteric site providing insights for the future optimization of this class of RNase H inhibitors
- …
