Thyroid secretion rate of albino rats during growth, pregnancy and lactation

Publication authorized September 17, 1946.Digitized 2007 AES.Includes bibliographical references (pages 32-34)

The metabolism of thyroxine

Digitized 2007 AES.Includes bibliographical references (pages 69-76)

Age-differential relationships among dopamine D1 binding potential, fusiform BOLD signal, and face-recognition performance

Facial recognition ability declines in adult aging, but the neural basis for this decline remains unknown. Cortical areas involved in face recognition exhibit lower dopamine (DA) receptor availability and lower blood-oxygen-level-dependent (BOLD) signal during task performance with advancing adult age. We hypothesized that changes in the relationship between these two neural systems are related to age differences in face-recognition ability. To test this hypothesis, we leveraged positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to measure D1 receptor binding potential (BPND) and BOLD signal during facerecognition performance. Twenty younger and 20 older participants performed a face-recognition task during fMRI scanning. Face recognition accuracy was lower in older than in younger adults, as were D1 BPND and BOLD signal across the brain. Using linear regression, significant relationships between DA and BOLD were found in both age-groups in face-processing regions. Interestingly, although the relationship was positive in younger adults, it was negative in older adults (i.e., as D1 BPND decreased, BOLD signal increased). Ratios of BOLD:D1 BPND were calculated and relationships to face-recognition performance were tested. Multiple linear regression revealed a significant Group BOLD:D1 BPND Ratio interaction. These results suggest that, in the healthy system, synchrony between neurotransmitter (DA) and hemodynamic (BOLD) systems optimizes the level of BOLD activation evoked for a given DA input (i.e., the gain parameter of the DA input-neural activation function), facilitating task performance. In the aged system, however, desynchronization between these brain systems would reduce the gain parameter of this function, adversely impacting task performance and contributing to reduced face recognition in older adults

The Ontology of Intentional Agency in Light of Neurobiological Determinism: Philosophy Meets Folk Psychology

The moot point of the Western philosophical rhetoric about free will consists in examining whether the claim of authorship to intentional, deliberative actions fits into or is undermined by a one-way causal framework of determinism. Philosophers who think that reconciliation between the two is possible are known as metaphysical compatibilists. However, there are philosophers populating the other end of the spectrum, known as the metaphysical libertarians, who maintain that claim to intentional agency cannot be sustained unless it is assumed that indeterministic causal processes pervade the action-implementation apparatus employed by the agent. The metaphysical libertarians differ among themselves on the question of whether the indeterministic causal relation exists between the series of intentional states and processes, both conscious and unconscious, and the action, making claim for what has come to be known as the event-causal view, or between the agent and the action, arguing that a sort of agent causation is at work. In this paper, I have tried to propose that certain features of both event-causal and agent-causal libertarian views need to be combined in order to provide a more defendable compatibilist account accommodating deliberative actions with deterministic causation. The ‘‘agent-executed-eventcausal libertarianism’’, the account of agency I have tried to develop here, integrates certain plausible features of the two competing accounts of libertarianism turning them into a consistent whole. I hope to show in the process that the integration of these two variants of libertarianism does not challenge what some accounts of metaphysical compatibilism propose—that there exists a broader deterministic relation between the web of mental and extra-mental components constituting the agent’s dispositional system—the agent’s beliefs, desires, short-term and long-term goals based on them, the acquired social, cultural and religious beliefs, the general and immediate and situational environment in which the agent is placed, etc. on the one hand and the decisions she makes over her lifetime on the basis of these factors. While in the ‘‘Introduction’’ the philosophically assumed anomaly between deterministic causation and the intentional act of deciding has been briefly surveyed, the second section is devoted to the task of bridging the gap between compatibilism and libertarianism. The next section of the paper turns to an analysis of folk-psychological concepts and intuitions about the effects of neurochemical processes and prior mental events on the freedom of making choices. How philosophical insights can be beneficially informed by taking into consideration folk-psychological intuitions has also been discussed, thus setting up the background for such analysis. It has been suggested in the end that support for the proposed theory of intentional agency can be found in the folk-psychological intuitions, when they are taken in the right perspective

Preliminary Research on a COVID-19 Test Strategy to Guide Quarantine Interval in University Students

Following COVID-19 exposure, the Centers for Disease Control (CDC) recommends a 10–14-day quarantine for asymptomatic individuals and more recently a 7-day quarantine with a negative PCR test. A university-based prospective cohort study to determine if early polymerase chain reaction (PCR) negativity predicts day 14 negativity was performed. A total of 741 asymptomatic students in quarantine was screened and 101 enrolled. Nasopharyngeal swabs were tested on days 3 or 4, 5, 7, 10, and 14, and the proportion of concordant negative results for each day versus day 14 with a two-sided 95% exact binomial confidence interval was determined. Rates of concordant negative test results were as follows: day 5 vs. day 14 = 45/50 (90%, 95% CI: 78–97%); day 7 vs. day 14 = 47/52 (90%, 95% CI: 79–97%); day 10 vs. day 14 = 48/53 (91%, 95% CI:79–97%), with no evidence of different negative rates between earlier days and day 14 by McNemar’s test, p \u3e 0.05. Overall, 14 of 90 (16%, 95% CI: 9–25%) tested positive while in quarantine, with seven initial positive tests on day 3 or 4, 5 on day 5, 2 on day 7, and none on day 10 or 14. Based on concordance rates between day 7 and 14, we anticipate that 90% (range: 79–97%) of individuals who are negative on day 7 will remain negative on day 14, providing the first direct evidence that exposed asymptomatic students ages 18–44 years in a university setting are at low risk if released from quarantine at 7 days if they have a negative PCR test prior to release. In addition, the 16% positive rate supports the ongoing need to quarantine close contacts of COVID-19 cases

A Technology-Mediated Behavioral Weight Gain Prevention Intervention for College Students: Controlled, Quasi-Experimental Study

BACKGROUND: Both men and women are vulnerable to weight gain during the college years, and this phenomenon is linked to an increased risk of several chronic diseases and mortality. Technology represents an attractive medium for the delivery of weight control interventions focused on college students, given its reach and appeal among this population. However, few technology-mediated weight gain prevention interventions have been evaluated for college students. OBJECTIVE: This study examined a new technology-based, social media-facilitated weight gain prevention intervention for college students. METHODS: Undergraduates (n =58) in two sections of a public university course were allocated to either a behavioral weight gain prevention intervention (Healthy Weight, HW; N=29) or a human papillomavirus (HPV) vaccination awareness intervention (control; N=29). All students were enrolled, regardless of initial body weight or expressed interest in weight management. The interventions delivered 8 lessons via electronic newsletters and Facebook postings over 9 weeks, which were designed to foster social support and introduce relevant educational content. The HW intervention targeted behavioral strategies to prevent weight gain and provided participants with a Wi-Fi-enabled scale and an electronic physical activity tracker to facilitate weight regulation. A repeated-measures analysis of variance was conducted to examine within- and between-group differences in measures of self-reported weight control practices and objectively measured weight. Use of each intervention medium and device was objectively tracked, and intervention satisfaction measures were obtained. RESULTS: Students remained weight stable (HW: -0.48+1.9 kg; control: -0.45+1.4 kg), with no significant difference between groups over 9 weeks (P =.94). However, HW students reported a significantly greater increase in the number of appropriate weight control strategies than did controls (2.1+4.5 vs -1.1+3.4, respectively; P =.003) and there was no increase in inappropriate weight control behaviors (P =.11). More than 90% of students in the HW arm opened the electronic newsletters each week, and the average number of Facebook interactions (comments and likes) per student each week was 3.3+1.4. Each self-monitoring device was initialized by 90% of HW students. On average, they used their physical activity tracker for 23.7+15.2 days and their Wi-Fi scale for 14.1+13.1 days over the 9 weeks. HW students rated the intervention favorably. CONCLUSIONS: The short-term effect of this technology-based weight gain prevention intervention for college students is promising and merits evaluation over a longer duration to determine whether engagement and behavioral improvements positively affect weight outcomes and can be maintained

College Freshmen Students’ Perspectives on Weight Gain Prevention in the Digital Age: Web-Based Survey

BACKGROUND: College freshmen are highly vulnerable to experiencing weight gain, and this phenomenon is associated with an increased risk of chronic diseases and mortality in older adulthood. Technology offers an attractive and scalable way to deliver behavioral weight gain prevention interventions for this population. Weight gain prevention programs that harness the appeal and widespread reach of Web-based technologies (electronic health or eHealth) are increasingly being evaluated in college students. Yet, few of these interventions are informed by college students\u27 perspectives on weight gain prevention and related lifestyle behaviors. OBJECTIVE: The objective of this study was to assess college freshmen students\u27 concern about weight gain and associated topics, as well as their interest in and delivery medium preferences for eHealth programs focused on these topics. METHODS: Web-based surveys that addressed college freshmen students\u27 (convenience sample of N=50) perspectives on weight gain prevention were administered at the beginning and end of the fall 2015 semester as part of a longitudinal investigation of health-related issues and experiences in first semester college freshmen. Data on weight gain prevention-related concerns and corresponding interest in eHealth programs targeting topics of potential concern, as well as preferred program delivery medium and current technology use were gathered and analyzed using descriptive statistics. RESULTS: A considerable proportion of the freshmen sample expressed concern about weight gain (74%, 37/50) and both traditional (healthy diet: 86%, 43/50; physical activity: 64%, 32/50) and less frequently addressed (stress: 82%, 41/50; sleep: 74%, 37/50; anxiety and depression: 60%, 30/50) associated topics within the context of behavioral weight gain prevention. The proportion of students who reported interest in eHealth promotion programs targeting these topics was also generally high (ranging from 52% [26/50] for stress management to 70% [35/50] for eating a healthy diet and staying physically active). Email was the most frequently used electronic platform, with 96% (48/50) of students reporting current use of it. Email was also the most frequently cited preferred eHealth delivery platform, with 86% (43/50) of students selecting it. Facebook was preferred by the second greatest proportion of students (40%, 20/50). CONCLUSIONS: Most college freshmen have concerns about an array of weight gain prevention topics and are generally open to the possibility of receiving eHealth interventions designed to address their concerns, preferably via email compared with popular social media platforms. These preliminary findings offer a foundation to build upon when it comes to future descriptive investigations focused on behavioral weight gain prevention among college freshmen in the digital age

Evaluating a Technology-Mediated HPV Vaccination Awareness Intervention: A Controlled, Quasi-Experimental, Mixed Methods Study

College-aged women and men are an important catch-up population for human papillomavirus (HPV) vaccination interventions. Limited research has explored technology-mediated HPV vaccination awareness interventions aimed at college students. The purpose was to evaluate a novel, technology-mediated, social media-based intervention to promote HPV vaccination among college students. A controlled, quasi-experimental, mixed methods study examined the feasibility of a technology-based intervention among two undergraduate classes ( = 58) at a public university in the southeastern United States of America. Classes were randomized to receive one of two cancer prevention programs (i.e., HPV vaccination (intervention) or healthy weight (control)). Both programs contained eight technology-mediated sessions, including weekly emails and private Facebook group posts. Participants completed pre-/post-test surveys and submitted weekly qualitative reflections. Data were analyzed using descriptive statistics and thematic review for qualitative data. Knowledge improved among participants in the HPV vaccination intervention relative to those in the control condition. Participants (97%) interacted on Facebook by liking a post or comment or posting a comment. Participants demonstrated robust engagement and high treatment satisfaction. Results suggests that social media is an effective platform to reach college students with health promotion interventions and increase HPV vaccination awareness in this important catch-up population

Social class and gender patterning of insomnia symptoms and psychiatric distress: a 20-year prospective cohort study

Background: Psychiatric distress and insomnia symptoms exhibit similar patterning by gender and socioeconomic position. Prospective evidence indicates a bi-directional relationship between psychiatric distress and insomnia symptoms so similarities in social patterning may not be coincidental. Treatment for insomnia can also improve distress outcomes. We investigate the extent to which the prospective patterning of distress over 20 years is associated with insomnia symptoms over that period.Methods: 999 respondents to the Twenty-07 Study had been followed for 20 years from approximately ages 36-57 (73.2% of the living baseline sample). Psychiatric distress was measured using the GHQ-12 at baseline and at 20-year follow-up. Gender and social class were ascertained at baseline. Insomnia symptoms were self-reported approximately every five years. Latent class analysis was used to classify patterns of insomnia symptoms over the 20 years. Structural Equation Models were used to assess how much of the social patterning of distress was associated with insomnia symptoms. Missing data was addressed with a combination of multiple-imputation and weighting.Results: Patterns of insomnia symptoms over 20 years were classified as either healthy, episodic, developing or chronic. Respondents from a manual social class were more likely to experience episodic, developing or chronic patterns than those from non-manual occupations but this was mostly explained by baseline psychiatric distress. People in manual occupations experiencing psychiatric distress however were particularly likely to experience chronic patterns of insomnia symptoms. Women were more likely to experience a developing pattern than men, independent of baseline distress. Psychiatric distress was more persistent over the 20 years for those in manual social classes and this effect disappeared when adjusting for insomnia symptoms. Irrespective of baseline symptoms, women, and especially those in a manual social class, were more likely than men to experience distress at age 57. This overall association for gender, but not the interaction with social class, was explained after adjusting for insomnia symptoms. Sensitivity analyses supported these findings.Conclusions: Gender and socioeconomic inequalities in psychiatric distress are strongly associated with inequalities in insomnia symptoms. Treatment of insomnia or measures to promote healthier sleeping may therefore help alleviate inequalities in psychiatric distress. © 2014 Green et al.; licensee BioMed Central Ltd