A new method for studying the vibration of non-homogeneous membranes

We present a method to solve the Helmholtz equation for a non-homogeneous membrane with Dirichlet boundary conditions at the border of arbitrary two-dimensional domains. The method uses a collocation approach based on a set of localized functions, called "little sinc functions", which are used to discretize two-dimensional regions. We have performed extensive numerical tests and we have compared the results obtained with the present method with the ones available from the literature. Our results show that the present method is very accurate and that its implementation for general problems is straightforward.Comment: 16 pages, 7 figures, 6 table

Orangutans (Pongo pygmaeus) do not Form Expectations Based on Their Partner’s Outcomes

Several primate species form expectations based on other’s outcomes. These individuals respond negatively when their outcomes differ from their partners’. The function and evolutionary pathway of this behavior are unknown, in part because all of the species which have thus far shown the response have similar life history patterns. In particular, all share traits related to a gregarious lifestyle, intelligence, and cooperativeness. The goal of the current paper was to test whether inequity is a homology among primates or a convergence based on some other characteristic by comparing one species known to show social comparisons, the chimpanzee, to another great ape which differs on several of these life history characteristics. Using a protocol identical to one used previously with chimpanzees, we tested whether orangutans, an intelligent but predominantly solitary species with few opportunities to cooperate, responded similarly. To allow for a strong comparison with chimpanzees (and other species), we used socially housed adults of both sexes, tested with members of their social group. We find that orangutans do not respond negatively to inequity, supporting previous findings and indicating that inequity responses in apes are likely a convergence based on either sociality or cooperative tendency. These results in such closely related species highlight the need for additional comparative studies to better understand the function and evolution of social behaviors

Vegetation and Invertebrate Community Response to Eastern Hemlock Decline in Southern New England

The introduction of Adelges tsugae (Hemlock Woolly Adelgid [HWA]) to the eastern United States has had a devastating impact on Tsuga canadensis (Eastern Hemlock). Although much research has been done to assess HWA impacts on ecosystem processes and vegetation structure, few researchers have examined community-level changes in highly infested forest stands. Here we assess the impact of Eastern Hemlock mortality on vegetation and invertebrate diversity and community structure by comparing low-impact (healthy) stands and stands heavily impacted by HWA. We sampled the vegetative and invertebrate diversity of 8 sites (4 low impact and 4 high impact) in the summer and fall of 2008. We found a shift in the understory plant community and the canopy and subcanopy arthropod communities. Herbaceous plant species richness was significantly higher at high-impact sites, with Betula lenta (Black Birch) being the most common woody species. Overall, forest invertebrate community diversity (measured using the Shannon-Weaver diversity index) was greater in high- versus low-impact sites. Of the 21 indicator species significantly associated with a given forest type, 14 and 7 species were associated with high- and low-impact forests, respectively. Variation in arthropod community structure was driven by above-ground differences; ground-level arthropod community composition did not differ between high- and low-impact sites. These results demonstrate some of the biodiversity impacts that can result from the invasion of an exotic insect into forested systems

The contested zone: interviews with GPs about their beliefs about treatment-resistant depression

BACKGROUND: Treatment-resistant depression (TRD) is when antidepressants do not work and affects 55% of British primary care users with depression. People with TRD should be referred to secondary care but there are long wait times. This means most people are managed by GPs, but primary care guidelines are not standardised. Thus, how GPs manage people with TRD may vary, and there is limited evidence for how quality care may look. As a result of this variation, an investigation into how GPs manage people might be valuable. AIM: To understand and interpret how GPs make decisions about treatment for people with potential TRD. METHOD: Fourteen GPs were interviewed by AT, patient-led researcher with bipolar, and LH, a GP. Interviews started with a vignette where someone did not respond to antidepressants. We followed up with semi-structured questions. Data were transcribed verbatim and analysed thematically. RESULTS: GPs gave eleven explanations for antidepressant ineffectiveness before and instead of TRD. Explanations included misdiagnosis, medicalised misery, not yet found the right antidepressant, believing too much in antidepressants, and not engaging with psychological interventions. We interpreted that the prioritisation of these explanations suggests that TRD can be contested diagnosis. This interpretation was not only latent but overt in our data: 'I think if we call things TRD, we undermine the impact of those other changes.' CONCLUSION: TRD can be a contested diagnosis in the same way as ADHD, ME, and long-COVID. GP training and continuing professional development may support GP awareness of TRD and help them in confidently making the diagnosis

Conceptualisations of health in orthorexia nervosa: a mixed-methods study

Purpose Limited research has explored conceptualisations of health and healthy eating in orthorexia nervosa (ON). This mixed-methods study aimed to investigate how ‘health’ and ‘healthy eating’ are conceptualised by individuals at risk for ON. This study examined the potential relationships between health anxiety, beliefs about health controllability and orthorexic symptomatology in our broader sample. Methods A total of 362 participants took a survey on health anxiety (measured with the HAQ), beliefs about the controllability of one’s own health (IMHLC) and ON symptomatology (E-DOS and EHQ). Participants ‘at risk’ for ON (n=141), also completed an online qualitative survey about conceptualisations of health and healthy eating. Qualitative data were analysed using thematic analysis (part A). The PROCESS macro for SPSS was used for the quantitative analysis (part B). Results Conceptualisations of health and healthy eating were complex. Four themes were generated from our qualitativedata: ‘health is more than thin ideals’, ‘healthy food equals healthy mind’, ‘a body that works for you’ and ‘taking control of your body’. Our quantitative analysis revealed that health anxiety and beliefs in health controllability independently predicted ON symptomatology. Conclusion A richer understanding of what health means in the context of ON is important, given the centrality of this concept to the proposed classifcation of this disordered eating style. Our fndings highlight that both health anxiety and health controllability are important targets for future investigation, given their potential relevance to the aetiology and treatment of ON

Experiencing EVA Park, A Multi-User Virtual World For People With Aphasia

Virtual worlds are used in wide-ranging ways by many people with long-term health conditions but their use by people with aphasia (PWA) has been limited. In contrast, this paper reports the use of EVA Park, a multi-user virtual world designed for PWA to practice conversations, focusing on people's emotional, social, and conversational experiences. An analysis of observation and interview data collected from 20 people with aphasia who participated in a 5 week therapy intervention revealed key themes related to user experience. The themes offer a rich insight into aspects of the virtual world experience for PWA that go beyond therapeutic outcomes. They are: affect (positive and negative), types of conversation, miscommunication and misunderstanding, immersion in the virtual world, social presence and initiative and flow. Overall, the study showed that participants experienced positive emotional and social outcomes. We argue that this was achieved as a consequence of EVA Park being not only accessible but also a varied and entertaining environment within which PWA experienced both the realistic and the quirky whilst engaging with others and having fun

RELSA—A multidimensional procedure for the comparative assessment of well-being and the quantitative determination of severity in experimental procedures

Good science in translational research requires good animal welfare according to the principles of 3Rs. In many countries, determining animal welfare is a mandatory legal requirement, implying a categorization of animal suffering, traditionally dominated by subjective scorings. However, how such methods can be objectified and refined to compare impairments between animals, subgroups, and animal models remained unclear. Therefore, we developed the RELative Severity Assessment (RELSA) procedure to establish an evidence-based method based on quantitative outcome measures such as body weight, burrowing behavior, heart rate, heart rate variability, temperature, and activity to obtain a relative metric for severity comparisons. The RELSA procedure provided the necessary framework to get severity gradings in TM-implanted mice, yielding four distinct RELSA thresholds L1<0.27, L2<0.59, L3<0.79, and L4<3.45. We show further that severity patterns in the contributing variables are time and model-specific and use this information to obtain contextualized between animal-model and subgroup comparisons with the severity of sepsis > surgery > restraint stress > colitis. The bootstrapped 95% confidence intervals reliably show that RELSA estimates are conditionally invariant against missing information but precise in ranking the quantitative severity information to the moderate context of the transmitter-implantation model. In conclusion, we propose the RELSA as a validated tool for an objective, computational approach to comparative and quantitative severity assessment and grading. The RELSA procedure will fundamentally improve animal welfare, data quality, and reproducibility. It is also the first step toward translational risk assessment in biomedical research

Early evaluation of a DBT-informed online intervention for people with eating disorders

Objectives Eating disorders (EDs) have a worldwide prevalence of 7.8%, with towering mortality rates and high healthcare costs. The current recommended treatment for EDs principally works by directly targeting ED thoughts and behaviours, but recovery rates are low. A multifaceted link between difficulties with emotions and EDs is now widely established, and newer third-wave therapies that aim to address these underlying emotion difficulties are promising. The current study piloted an online emotion self-help intervention which was co-developed with clinicians and people with lived experienced of EDs. The intervention aimed to specifically address difficulties with emotion identification and regulation, as well as unhelpful beliefs about emotions, which are believed to give rise to and maintain ED thoughts and behaviours. Method We recruited 39 people with self-reported EDs to test this intervention over a one-week period. Our participants were asked to complete a series of questionnaires measuring emotion processes and psychopathology on Day 1 (T1) before being given access to the intervention. Participants were then asked to practice the newly acquired skills for seven days, before taking the same questionnaires on Day 9 (T2). We also asked participants to qualitatively report on their experience of the intervention. Results We found significant improvements in ED psychopathology (ED-15), depression (PHQ-9), and anxiety (GAD-7) pre- to post-intervention, with medium to large effect sizes. All our emotion variables namely alexithymia (TAS-20), difficulties regulating emotions (DERS-SF), and unhelpful beliefs about emotions (EBQ) also showed significant changes post-intervention with medium to large effect sizes. Most importantly, changes in emotion regulation processes were linked to improved eating psychopathology. The qualitative analysis corroborated this finding, highlighting how the intervention helped them form new beliefs about emotions, which helped them reduce ED behaviours. Discussion Significant improvements in emotion processing and regulations, as well as psychopathology, along with positive qualitative feedback, suggest that the intervention effectively met its aims of increasing awareness of the link between emotions and eating psychopathology, providing help to identify and regulate emotions, and normalising emotional experiences. While our results are promising, further research is required to assess its effectiveness longer term and in clinical settings

Striving for the perfect diet? The mediating role of perfectionism in the relationship between obsessive compulsive symptoms and traits of Orthorexia Nervosa

Background: Orthorexia Nervosa (ON) is a disordered eating style involving an unhealthy obsession with ‘healthy’ or ‘clean’ eating. Its aetiology is still poorly understood and is not yet recognised in diagnostic manuals. While ON has been associated with Obsessive Compulsive (OC) symptoms and perfectionism, no study to date has looked at the relationship between OC symptoms and ON tendencies via perfectionism, or the influence of two facets of perfectionism in this relationship, namely evaluative concern and achievement striving. Examining the potential role of perfectionism helps to understand the aetiology of ON as well as inform potential treatments tailored specifically for ON and comorbid OC symptoms. Methods: In this cross sectional study, we tested 507 participants (n = 70 males, n = 69 at risk of ON) on questionnaires measuring OC symptoms, perfectionism and ON symptoms. We ran two mediation analyses to look at the overall relationship between perfectionism and OC and ON symptoms (Model 1) as well as the specific contribution of evaluative concern and achievement striving in the relationship between OC and ON symptoms (Model 2). Results: We found that perfectionism partially mediated the relationship between OC and ON symptoms. Specifically, we found that while achievement striving and evaluative concern were associated with OC symptoms, only achievement striving was significantly associated with ON symptoms, mediating the relationship between OC and ON symptoms. Conclusions: This study highlighted the role of one key facet of perfectionism (achievement striving) in the aetiology of ON. The role of achievement striving was indicated as a transdiagnostic construct explaining the link between ON and OC symptoms. These findings are discussed in terms of their implications for treatment models, specifically in terms of the potential role of targeting perfectionism in ON treatment