The effects of phosphatidylserine on endocrine response to moderate intensity exercise

Previous research has indicated that phosphatidylserine (PS) supplementation has the potential to attenuate the serum cortisol response to acute exercise stress. Equivocal findings suggest that this effect might be dose dependent. This study aimed to examine the influence of short-term supplementation with a moderate dose of PS (600 mg per day) on plasma concentrations of cortisol, lactate, growth hormone and testosterone before, during, and following moderate intensity exercise in healthy males. 10 healthy male subjects participated in the study. Each subject was assigned to ingest 600 mg PS or placebo per day for 10 days using a double-blind, placebo-controlled, crossover design. Serial venous blood samples were taken at rest, after a 15 minute moderate intensity exercise protocol on a cycle ergometer that consisted of five 3-minute incremental stages beginning at 65% and ending at 85% VO2 max, and during a 65 minute passive recovery. Plasma samples were assessed for cortisol, growth hormone, testosterone, lactate and testosterone to cortisol ratio for treatment (PS or placebo). Mean peak cortisol concentrations and area under the curve (AUC) were lower following PS (39 ± 1% and 35 ± 0%, respectively) when compared to placebo (p < 0.05). PS increased AUC for testosterone to cortisol ratio (184 ± 5%) when compared to placebo (p < 0.05). PS and placebo supplementation had no effect on lactate or growth hormone levels. The findings suggest that PS is an effective supplement for combating exercise-induced stress and preventing the physiological deterioration that can accompany too much exercise. PS supplementation promotes a desired hormonal status for athletes by blunting increases in cortisol levels

Glycinergic feedback enhances synaptic gain in the distal retina

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of the Physiological Society for personal use, not for redistribution. The definitive version was published in Journal of Physiology 592 (2014): 1479-1492, doi:10.1113/jphysiol.2013.265785.Glycine input originates with interplexiform cells, a group of neurons situated within the inner retina that transmit signals centrifugally to the distal retina. The effect on visual function of this novel mechanism is largely unknown. Using gramicidin-perforated patch whole-cell recordings, intracellular recordings, and specific antibody labeling techniques, we examined the effects of the synaptic connections between glycinergic interplexiform cells, photoreceptors, and bipolar cells. To confirm that interplexiform cells make centrifugal feedback on bipolar cell dendrites, we recorded the post-synaptic glycine currents from axon-detached bipolar cells while stimulating pre-synaptic interplexiform cells. The results show that glycinergic interplexiform cells activate bipolar cell dendrites that express the α3 subunit of the glycine receptor, as well as a subclass of unidentified receptors on photoreceptors. By virtue of their synaptic contacts, glycine centrifugal feedback increases glutamate release from photoreceptors, and suppresses the uptake of glutamate by the EAAT2 transporter on photoreceptors. The net effect is a significant increase in the synaptic gain between photoreceptors and their second-order neurons.This study was supported by grants from the National Science Foundation (NSF, IOS-1021646, WS) and the National Eye Institute (NEI, EY 14161, WS)

Characteristics Related to Parent-Child Literacy and Numeracy Practices in Preschool

Despite evidence suggesting that home literacy and numeracy environments are related to children’s school readiness skills, little research has examined the child and family characteristics that relate to the home literacy and numeracy environments within the same sample. These factors are important to investigate in order to determine what may foster or prevent parent-child engagement. The primary purpose of this study was to examine the shared and unique parent-reported child and parent variables that are related to the frequency of parent-child literacy and numeracy practices. The 199 preschoolers included in the study ranged in age from 3.00 to 5.17° years (M= 4.16, SD = 0.57). Parents reported on child and family characteristics. Two multiple regression analyses were conducted (one each for home literacy and numeracy environments). Results indicated that parent education and children’s age were positively related to the frequency of both literacy and numeracy practices. However, parents’ beliefs of the importance of numeracy were positively associated with the frequency of parent-reported numeracy practices, whereas beliefs of the importance of literacy were not related to the frequency of literacy practices. In line with other research, parents reported finding literacy development to be more important than numeracy development and engaging in parent-child literacy practices more frequently than numeracy practices. Understanding factors that are related to the home literacy and numeracy environments may be an important step in identifying how to best encourage parents to engage their children in these practices at home

Why do early mathematics skills predict later mathematics and reading achievement? The role of executive function

A robust association between young children’s early mathematical proficiency and later academic achievement is well established. Less is known about the mechanisms through which early mathematics skills may contribute to later mathematics and especially reading achievement. Using a parallel multiple mediator model, the current study investigated whether executive function (integration of working memory, inhibition, and cognitive flexibility) can explain the relations between early mathematics skills and elementary school mathematics and reading achievement. Data in this longitudinal study were collected from 243 children during the last year of early childhood education and care (kindergarten ages 5 and 6 years), 1 year later in first grade, and 5 years later when the children were in fifth grade. Background variables (maternal education, age, sex, and immigrant status), kindergarten baseline skills, and mediating effects of first-grade mathematics, phonological awareness, vocabulary, and possible omitted variables were controlled. Results showed that first-grade executive function mediated the effects of kindergarten mathematics on fifth-grade mathematics and on reading achievement. These findings suggest that executive function may work as a mechanism that may help to explain the frequently found strong association between children’s early mathematics skills and later mathematics and reading achievement.publishedVersio

Examining the Factor Structure of the Home Mathematics Environment to Delineate Its Role in Predicting Preschool Numeracy, Mathematical Language, and Spatial Skills

A growing body of evidence suggests that the ways in which parents and preschool children interact in terms of home-based mathematics activities (i.e., the home mathematics environment; HME) is related to children’s mathematics development (e.g., primarily numeracy skills and spatial skills); however, this body of evidence is mixed with some research supporting the relation and others finding null effects. Importantly, few studies have explicitly examined the factor structure of the HME and contrasted multiple hypothesized models. To develop more precise models of how the HME supports children’s mathematics development, the structure of the HME needs to be examined and linked to mathematics performance. The purpose of this study was to extend prior work by replicating the factor structure of the HME (as one general HME factor and three specific factors of direct numeracy, indirect numeracy, and spatial) and using those factors to predict direct assessments of children’s numeracy, mathematical language, and spatial skills. It was hypothesized that the general HME factor would be related to each direct assessment, the direct numeracy factor would be related to both numeracy and mathematical language, and the spatial factor would be related to spatial skills. Using a sample of 129 preschool children (M age = 4.71 years, SD = 0.55; 46.5% female), a series of confirmatory factor analyses were conducted. Results diverged somewhat from prior work as the best fitting model was a bifactor model with a general HME factor and two specific factors (one that combined direct and indirect numeracy activities and another of spatial activities) rather than three specific factors as had previously been found. Further, structural equation modeling analyses suggested that, in contrast to expectations, only the direct + indirect numeracy factor was a significant predictor of direct child assessments when accounting for age, sex, and parental education. These findings provide evidence that a bifactor model is important in understanding the structure of the HME, but only one specific factor is related to children’s outcomes. Delineating the structure of the HME, and how specific facets of the HME relate to children’s mathematics skills, provides a strong foundation for understanding and enhancing the mechanisms that support mathematics development

We are the Change that we Seek: Information Interactions During a Change of Viewpoint

There has been considerable hype about filter bubbles and echo chambers influencing the views of information consumers. The fear is that these technologies are undermining democracy by swaying opinion and creating an uninformed, polarised populace. The literature in this space is mostly techno-centric, addressing the impact of technology. In contrast, our work is the first research in the information interaction field to examine changing viewpoints from a human-centric perspective. It provides a new understanding of view change and how we might support informed, autonomous view change behaviour. We interviewed 18 participants about a self-identified change of view, and the information touchpoints they engaged with along the way. In this paper we present the information types and sources that informed changes of viewpoint, and the ways in which our participants interacted with that information. We describe our findings in the context of the techno-centric literature and suggest principles for designing digital information environments that support user autonomy and reflection in viewpoint formation

New-onset functional tics during the COVID-19 pandemic::Clinical characteristics of 105 cases from a single centre

Background and purpose The COVID-19 pandemic has been associated amongst other things with a sharp increase in adolescents and young adults presenting acutely with functional tics. Initial reports have suggested clinically relevant differences between functional tics and neurodevelopmental tics seen in primary tic disorders such as Tourette syndrome. We aimed to provide confirmatory findings from the largest single-centre cohort to date. Methods In the present study we present data from 105 consecutive patients who developed functional tics during a 3-year period overlapping with the COVID-19 pandemic (April 2020–March 2023). All patients underwent a comprehensive neuropsychiatric assessment at a single specialist centre for tic disorders. Results Female adolescents and young adults accounted for 69% of our sample. Functional tics had an acute/subacute onset in most cases (75% with a peak of severity within 1 month). We found a disproportionately high frequency of complex movements (81%) and vocalizations (75%). A subset of patients (23%) had a pre-existing primary tic disorder (Tourette syndrome with functional overlay). The most common psychiatric co-morbidities were anxiety (70%) and affective disorders (40%). Moreover, 41% of patients had at least one functional neurological disorder in addition to functional tics. Exposure to tic-related social media content was reported by half of the patients. Conclusions Our findings confirm substantial clinical differences between functional tics developed during the pandemic and neurodevelopmental tics. Both patient- and tic-related red flags support the differential diagnostic process and inform ongoing monitoring in the post-pandemic era

On Birthing Dancing Stars: The Need for Bounded Chaos in Information Interaction

While computers causing chaos is acommon social trope, nearly the entirety of the history of computing is dedicated to generating order. Typical interactive information retrieval tasks ask computers to support the traversal and exploration of large, complex information spaces. The implicit assumption is that they are to support users in simplifying the complexity (i.e. in creating order from chaos). But for some types of task, particularly those that involve the creative application or synthesis of knowledge or the creation of new knowledge, this assumption may be incorrect. It is increasingly evident that perfect order—and the systems we create with it—support highly-structured information tasks well, but provide poor support for less-structured tasks.We need digital information environments that help create a little more chaos from order to spark creative thinking and knowledge creation. This paper argues for the need for information systems that offerwhat we term ‘bounded chaos’, and offers research directions that may support the creation of such interface