Analysis of Multi-Directional Recycled Jute Fiber Composite Behavior Using Experimental, Numerical, and Analytical Methods

Composite materials are increasing in popularity as a material of choice in many engineering applications. Major industries using composites include automotive, construction, and sports equipment. Most of the knowledge, research, and technology that will help decrease the cost of composite materials have been aimed at developing synthetic fibers as the reinforcing constituent. This thesis characterizes jute fibers obtained as a byproduct from the coffee industry to determine if they can be viable in composite manufacturing. Experimental analysis, finite element analysis, and analytical modeling are used to characterize jute fiber based composites. Experimental analysis consists of jute fiber bundle tensile testing as well as tensile testing of multiple laminates. Finite element and analytical models were developed to simulate different composite characteristics and their influence on jute composites. Finite element models investigated the influences of fiber undulation, fiber damage, and matrix porosity. Results show that certain manufacturing precautions should be taken to minimize imperfections which have negative influences on the composite. Fiber damage has the largest influence when introduced near the top of the fiber wave and can cause normal stresses to increase 56%. Fiber undulation and matrix porosity also have noticeable influences on the composite

Online consultations in mental healthcare: Modelling determinants of use and experience based on an international survey study at the onset of the pandemic

Introduction: While online consultations have shown promise to be a means for the effective delivery of high -quality mental healthcare and the first implementations of these digital therapeutic contacts go back nearly two decades, uptake has remained limited over the years. The onset of the COVID-19 pandemic dramatically altered this relative standstill and created a unique turning point, with a massive amount of both professionals and clients having first hands-on experiences with technology in mental healthcare.Objective: The current study aimed to document the uptake of online consultations and explore if specific characteristics of mental health professionals across and beyond Europe could predict this.Methods: An international survey was designed to assess mental health professionals' (initial) experiences with online consultations at the onset of the pandemic: their willingness to make use of them and their prior and current experiences, alongside several personal characteristics. Logistic mixed-effects models were used to identify predictors of the use of online consultations, personal experience with this modality, and the sense of telepresence.Results: A total of 9115 healthcare professionals from 73 countries participated of which about two-thirds used online consultations during the initial COVID-19 outbreak. The current study identifies multiple determinants relating to the use and experience of online consultations, including the professionals' age, experience with the technology before the outbreak, the professional context, and training.Conclusions: Despite strong evidence supporting the relevance of training in digital mental health, this is clearly still lacking. Nevertheless, the COVID-19 pandemic presented a first, and potentially transformative, experience with online consultations for many healthcare professionals. The insights from this study can help supportprofessionals and, importantly, (mental) healthcare organisations to create optimal circumstances for selective and high-quality continued use of online consultations

Enhancing studies of the connectome in autism using the autism brain imaging data exchange II

The second iteration of the Autism Brain Imaging Data Exchange (ABIDE II) aims to enhance the scope of brain connectomics research in Autism Spectrum Disorder (ASD). Consistent with the initial ABIDE effort (ABIDE I), that released 1112 datasets in 2012, this new multisite open-data resource is an aggregate of resting state functional magnetic resonance imaging (MRI) and corresponding structural MRI and phenotypic datasets. ABIDE II includes datasets from an additional 487 individuals with ASD and 557 controls previously collected across 16 international institutions. The combination of ABIDE I and ABIDE II provides investigators with 2156 unique cross-sectional datasets allowing selection of samples for discovery and/or replication. This sample size can also facilitate the identification of neurobiological subgroups, as well as preliminary examinations of sex differences in ASD. Additionally, ABIDE II includes a range of psychiatric variables to inform our understanding of the neural correlates of co-occurring psychopathology; 284 diffusion imaging datasets are also included. It is anticipated that these enhancements will contribute to unraveling key sources of ASD heterogeneity

Oxytocin-based pharmacotherapy for Autism Spectrum Disorders: Investigating the neural and behavioural effects of a promising intervention approach

Oral presentation during the Fourth Symposium of the Marguerite-Marie Delacroix Foundation : Multidisciplinary Research Grants.status: publishe

Influence of oxytocin on emotion recognition: A randomized placebo-controlled trial

The neuropeptide ‘oxytocin’ (OT) is known to play a pivotal role in a variety of complex social behaviors. It is hypothesized that OT promotes prosocial behavior by enhancing the processing of socially-relevant information from the environment, such as facial expressions and bodily kinematics. As these behaviors are known to be deficient in people with an Autism Spectrum Disorder (ASD), more research is needed to assess OT as a potential therapeutic approach. With the present study, we explored the extent by which OT can enhance the ‘reading’ of emotional body language as presented in impoverished biological motion point light displays (PLDs). To this end, we adopted a double-blind, randomized placebo-controlled design to assess single-dose effects of intranasal OT administration. Eighty-six neurotypical male participants performed a bodily emotion recognition task before and after a single-dose of intranasal OT. Two experiments were conducted to assess whether the novelty of the presented emotional states contributes to recognition performance, one with identical and the other with novel PLD stimuli pre- and post-OT administration. Single-dose effects of OT administration on emotion recognition were moderate, indicating enhanced recognition of emotional body language when novel emotional stimuli were presented post-OT administration. Yet when identical emotional stimuli were presented at baseline and post-OT administration, results indicated a general learning effect rather than specific enhancements related to the OT administration. Although the effects were moderate, they provide indications that OT might form a promising target for development of novel treatments for patient populations with particular social deficits such as ASD.status: publishe

Effects of single- and multiple-dose oxytocin treatment on amygdala low-frequency BOLD fluctuations and BOLD spectral dynamics in autism

Prior neuroimaging clinical trials investigating the neural effects of intranasal administration of the neuropeptide oxytocin demonstrated a key role of the amygdala in oxytocin's neuromodulatory effects. These studies mostly demonstrated the acute effects of single-dose administrations, examining task-dependent effects of oxytocin on brain activity elicited during explicit experimental tasks or stimuli presentations. The increased consideration of oxytocin as a potential ameliorating treatment in autism spectrum disorder (ASD) requires a better understanding of how multiple-dose oxytocin administration affects intrinsic, task-free, amygdala function. In this double-blind, randomized, placebo-controlled trial with between-subject design, 38 adult men with ASD underwent resting-state fMRI scanning before and after oxytocin or placebo treatment. Effects were assessed either after a single-dose administration, consisting of 24 international units, or after multiple-dose treatment, consisting of 4 weeks of once-daily nasal spray administrations. Compared to placebo, oxytocin induced a decrease in intrinsic resting-state BOLD signal amplitudes of the bilateral amygdala (fractional amplitudes of low-frequency fluctuations) and modulated cross-frequency interactions between adjacent BOLD frequency components. The right amygdala showed a pattern of reduced cross-frequency harmonicity, while the left amygdala showed a relative increase in harmonic cross-frequency interactions after oxytocin treatment. Notably, the direction and magnitude of BOLD spectral changes induced after a single-dose were qualitatively similar to treatment effects induced after multiple-dose treatment. Furthermore, the identified spectral changes in amygdalar BOLD amplitude and cross-frequency harmonicity were associated with improved feelings of tension, reflecting oxytocin's anxiolytic, stress-reducing neuromodulatory role. The observed effects of oxytocin on amygdalar BOLD spectral characteristics and associated behaviors contribute to a deeper mechanistic understanding of the intrinsic, task-free neuromodulatory dynamics that underlie single- and multiple-dose oxytocin treatment in ASD. European Clinical Trial Registry (Eudract 2014-000586-45).ISSN:2158-318

One-year retention effects of multiple-dose oxytocin treatment on repetitive behaviors, social responsiveness and attachment: A randomized, placebo-controlled trial.

Poster presentation at INSAR 2018status: publishe

The Effects of Four Weeks of Intranasal Oxytocin on Social Responsiveness and Repetitive and Restricted Behaviors in Autism Spectrum Disorders: A Randomized Controlled Trial

The effects of four weeks of intranasal oxytocin on social responsiveness and repetitive and restricted behaviors in autism spectrum disorders: A randomized controlled trial. S. Bernaerts, C. Dillen, J. Steyaert, and K. Alaerts Background: Autism spectrum disorders (ASDs) are characterized by impairments in social communication and interaction and repetitive and restricted behaviors. To date, no pharmacological treatment exists targeting the core symptoms of ASD, yet the past years, the pharmacological use of a neuropeptide, called oxytocin (OT), has gained increasing interest from the research community to explore its potential for elevating the core social deficits in ASD. OT is known to play a pivotal role in a variety of complex social behaviors by promoting a prosocial attitude and interpersonal bonding. Previous studies showed that exogenously administered OT can affect trust and feelings of attachment insecurity, reduce repetitive and restricted behaviors and increase social cognition. Objectives: A double-blind randomized placebo-controlled trial with thirty-four young adult men with ASD (17 OT/ 17 Placebo (PL)) was conducted to assess behavioral effects of OT therapy (i) at baseline; (ii) after four weeks of daily nasal spray administration; and (iii) four weeks post-treatment to assess potential retention effects. Methods: Doses of 24 IU oxytocin (Syntocinon®, Sigma-tau) or placebo nasal spray (PL) (saline natrium-chloride solution) (3 puffs in each nostril) were administered daily for four weeks. Primary outcome measures to assess treatment effects included the Social Responsiveness Scale (SRS) and the Repetitive Behavior Scale – Revised (RBS-R). Secondary outcome measures included assessments of changes in attachment (State Adult Attachment Scale (SAAM); Inventory of Parent and Peer Attachment (IPPA)); assessments of changes in mood state (Profile of Mood States questionnaire (POMS)); and assessments of changes is reports of quality of life (World Health Organization Quality of Life questionnaire (WHOQOL)). All participants were characterized using IQ and ADOS-scales. Thirty-four male individuals with ASD are currently enrolled in the study and recruitment is still ongoing. Results: After four weeks of OT nasal spray administration, self-reports on repetitive and restricted behaviors (RBS-R) were shown to be tentatively reduced in the OT group, not in the PL group (F(1, 31)=3.83, p=0.06) and of note, the effect of OT persisted until one month after the treatment (retention: F(1, 31)=4.02, p=0.05). Immediately after the four weeks of treatment, we found no significant effects of OT on social functioning as assessed using self- and informant-based reports of the SRS. Interestingly however, at the retention session, a significant effect was revealed for the informant-based SRS (F(1, 22)=4.90, p=0.04), indicating that clear improvements in social responsiveness emerged one month after cessation of the actual treatment (specifically for reports of social motivation (F(1, 22)=4.71, p=0.04) and social communication (F(1, 22)=7.39, p=0.01)). For the secondary outcome measures, only tentative effects were revealed, indicating improvements in self-reports of attachment immediately after the four-week treatment (F(1, 32)=3.32, p=0.08) (IPPA) and improvements in the experience of social relationships at the retention session one-month post-trial (F(1, 31)=3.07, p=0.09) (WHOQOL). Conclusions: The observed improvements after four weeks of daily treatment with intranasal OT in our primary outcome measures (assessing social responsiveness and repetitive and restricted behaviors) indicate that OT can induce long-term behavioral changes in individuals with ASD that outlast the time of intervention.status: accepte

One-year retention effects of multiple-dose oxytocin treatment on repetitive behaviors, social responsiveness and attachment: A randomized, placebo-controlled trial.

Poster presentation at the "oxytocin workshop" in Ericestatus: publishe