137 research outputs found
A Research-Based Educator\u27s Guide to Auditory Processing Disorder: Does it Improve Teachers\u27 Confidence?
Auditory processing disorder (APD) occurs in an estimated 5-10% of the population, yet many educators are unaware it even exists, let alone have confidence in how to support students in their classroom with this disorder. With a shortage of professional resources and training for teachers about APD, many educators struggle to understand the disorder and know what strategies and interventions to implement to help students with APD. After reading a guidebook of research-based information about APD specifically designed for educators, it was hypothesized teachers’ confidence levels in working with students with APD would increase. Forty-three participants responded to the initial part of the survey and indicated that they knew little about APD. Of those participants, 20 read the guidebook and completed the remainder of the survey. It was found educators did feel the guidebook was helpful in increasing their knowledge of APD and they felt more confident in knowing how to teach students with APD. With this guidebook about APD shown to be effective in improving teachers’ confidence, educators now have a reference that is research-based and teacher-friendly
Brief report: how adolescents with ASD process social information in complex scenes. Combining evidence from eye movements and verbal descriptions
We investigated attention, encoding and processing of social aspects of complex photographic scenes. Twenty-four high-functioning adolescents (aged 11–16) with ASD and 24 typically developing matched control participants viewed and then described a series of scenes, each containing a person. Analyses of eye movements and verbal descriptions provided converging evidence that both groups displayed general interest in the person in each scene but the salience of the person was reduced for the ASD participants. Nevertheless, the verbal descriptions revealed that participants with ASD frequently processed the observed person’s emotion or mental state without prompting. They also often mentioned eye-gaze direction, and there was evidence from eye movements and verbal descriptions that gaze was followed accurately. The combination of evidence from eye movements and verbal descriptions provides a rich insight into the way stimuli are processed overall. The merits of using these methods within the same paradigm are discussed
How the Rural Risk Environment Underpins Hepatitis C Risk: Qualitative Findings From Rural Southern Illinois, United States
Background: Hepatitis C virus (HCV) infection has increased among persons who inject drugs (PWID) in the United States with disproportionate burden in rural areas. We use the Risk Environment framework to explore potential economic, physical, social, and political determinants of hepatitis C in rural southern Illinois.
Methods: Nineteen in-depth semi-structured interviews were conducted with PWID from August 2019 through February 2020 (i.e., pre-COVID-19 pandemic) and four with key informants who professionally worked with PWID. Interviews were recorded, professionally transcribed, and coded using qualitative software. We followed a grounded theory approach for coding and analyses.
Results: We identify economic, physical, policy, and social factors that may influence HCV transmission risk and serve as barriers to HCV care. Economic instability and lack of economic opportunities, a lack of physically available HCV prevention and treatment services, structural stigma such as policies that criminalize drug use, and social stigma emerged in interviews as potential risks for transmission and barriers to care.
Conclusion: The rural risk environment framework acknowledges the importance of community and structural factors that influence HCV infection and other disease transmission and care. We find that larger structural factors produce vulnerabilities and reduce access to resources, which negatively impact hepatitis C disease outcomes
Ketamine effects on memory reconsolidation favor a learning model of delusions.
Delusions are the persistent and often bizarre beliefs that characterise psychosis. Previous studies have suggested that their emergence may be explained by disturbances in prediction error-dependent learning. Here we set up complementary studies in order to examine whether such a disturbance also modulates memory reconsolidation and hence explains their remarkable persistence. First, we quantified individual brain responses to prediction error in a causal learning task in 18 human subjects (8 female). Next, a placebo-controlled within-subjects study of the impact of ketamine was set up on the same individuals. We determined the influence of this NMDA receptor antagonist (previously shown to induce aberrant prediction error signal and lead to transient alterations in perception and belief) on the evolution of a fear memory over a 72 hour period: they initially underwent Pavlovian fear conditioning; 24 hours later, during ketamine or placebo administration, the conditioned stimulus (CS) was presented once, without reinforcement; memory strength was then tested again 24 hours later. Re-presentation of the CS under ketamine led to a stronger subsequent memory than under placebo. Moreover, the degree of strengthening correlated with individual vulnerability to ketamine's psychotogenic effects and with prediction error brain signal. This finding was partially replicated in an independent sample with an appetitive learning procedure (in 8 human subjects, 4 female). These results suggest a link between altered prediction error, memory strength and psychosis. They point to a core disruption that may explain not only the emergence of delusional beliefs but also their persistence
I Don\u27t Believe a Person Has to Die When Trying to Get High: Overdose Prevention and Response Strategies in Rural Illinois
BACKGROUND: Overdose is a leading cause of morbidity and mortality among people who inject drugs. Illicitly manufactured fentanyl is now a major driver of opioid overdose deaths.
METHODS: Semi-structured interviews were conducted with 23 participants (19 persons who inject drugs and 4 service providers) from rural southern Illinois. Data were analyzed using constant comparison and theoretical sampling methods.
RESULTS: Participants were concerned about the growing presence of fentanyl in both opioids and stimulants, and many disclosed overdose experiences. Strategies participants reported using to lower overdose risk included purchasing drugs from trusted sellers and modifying drug use practices by partially injecting and/or changing the route of transmission. Approximately half of persons who inject drugs sampled had heard of fentanyl test strips, however fentanyl test strip use was low. To reverse overdoses, participants reported using cold water baths. Use of naloxone to reverse overdose was low. Barriers to naloxone access and use included fear of arrest and opioid withdrawal.
CONCLUSIONS: People who inject drugs understood fentanyl to be a potential contaminant in their drug supply and actively engaged in harm reduction techniques to try to prevent overdose. Interventions to increase harm reduction education and information about and access to fentanyl test strips and naloxone would be beneficial
Attentional differences in a driving hazard perception task in adults with autism spectrum disorders
The current study explored attentional processing of social and non social stimuli in ASD within the context of a driving hazard perception task. Participants watched videos of road scenes and detected hazards while their eye movements were recorded. Although individuals with ASD demonstrated relatively good detection of driving hazards, they were slower to orient to hazards. Greater attentional capture in the time preceding the hazards’ onset was associated with lower verbal IQ. The findings suggest that individuals with ASD may distribute and direct their attention diferently when identifying driving hazards
BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers
Background: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers.
Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided.
Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed.
Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations
Learning, Memory, and the Role of Neural Network Architecture
The performance of information processing systems, from artificial neural networks to natural neuronal ensembles, depends heavily on the underlying system architecture. In this study, we compare the performance of parallel and layered network architectures during sequential tasks that require both acquisition and retention of information, thereby identifying tradeoffs between learning and memory processes. During the task of supervised, sequential function approximation, networks produce and adapt representations of external information. Performance is evaluated by statistically analyzing the error in these representations while varying the initial network state, the structure of the external information, and the time given to learn the information. We link performance to complexity in network architecture by characterizing local error landscape curvature. We find that variations in error landscape structure give rise to tradeoffs in performance; these include the ability of the network to maximize accuracy versus minimize inaccuracy and produce specific versus generalizable representations of information. Parallel networks generate smooth error landscapes with deep, narrow minima, enabling them to find highly specific representations given sufficient time. While accurate, however, these representations are difficult to generalize. In contrast, layered networks generate rough error landscapes with a variety of local minima, allowing them to quickly find coarse representations. Although less accurate, these representations are easily adaptable. The presence of measurable performance tradeoffs in both layered and parallel networks has implications for understanding the behavior of a wide variety of natural and artificial learning systems
Malignant hyperthermia
Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle that presents as a hypermetabolic response to potent volatile anesthetic gases such as halothane, sevoflurane, desflurane and the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat. The incidence of MH reactions ranges from 1:5,000 to 1:50,000–100,000 anesthesias. However, the prevalence of the genetic abnormalities may be as great as one in 3,000 individuals. MH affects humans, certain pig breeds, dogs, horses, and probably other animals. The classic signs of MH include hyperthermia to marked degree, tachycardia, tachypnea, increased carbon dioxide production, increased oxygen consumption, acidosis, muscle rigidity, and rhabdomyolysis, all related to a hypermetabolic response. The syndrome is likely to be fatal if untreated. Early recognition of the signs of MH, specifically elevation of end-expired carbon dioxide, provides the clinical diagnostic clues. In humans the syndrome is inherited in autosomal dominant pattern, while in pigs in autosomal recessive. The pathophysiologic changes of MH are due to uncontrolled rise of myoplasmic calcium, which activates biochemical processes related to muscle activation. Due to ATP depletion, the muscle membrane integrity is compromised leading to hyperkalemia and rhabdomyolysis. In most cases, the syndrome is caused by a defect in the ryanodine receptor. Over 90 mutations have been identified in the RYR-1 gene located on chromosome 19q13.1, and at least 25 are causal for MH. Diagnostic testing relies on assessing the in vitro contracture response of biopsied muscle to halothane, caffeine, and other drugs. Elucidation of the genetic changes has led to the introduction, on a limited basis so far, of genetic testing for susceptibility to MH. As the sensitivity of genetic testing increases, molecular genetics will be used for identifying those at risk with greater frequency. Dantrolene sodium is a specific antagonist of the pathophysiologic changes of MH and should be available wherever general anesthesia is administered. Thanks to the dramatic progress in understanding the clinical manifestation and pathophysiology of the syndrome, the mortality from MH has dropped from over 80% thirty years ago to less than 5%
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