A Bayesian approach to two-mode clustering

We develop a new Bayesian approach to estimate the parameters of a latent-class model for the joint clustering of both modes of two-mode data matrices. Posterior results are obtained using a Gibbs sampler with data augmentation. Our Bayesian approach has three advantages over existing methods. First, we are able to do statistical inference on the model parameters, which would not be possible using frequentist estimation procedures. In addition, the Bayesian approach allows us to provide statistical criteria for determining the optimal numbers of clusters. Finally, our Gibbs sampler has fewer problems with local optima in the likelihood function and empty classes than the EM algorithm used in a frequentist approach. We apply the Bayesian estimation method of the latent-class two-mode clustering model to two empirical data sets. The first data set is the Supreme Court voting data set of Doreian, Batagelj, and Ferligoj (2004). The second data set comprises the roll call votes of the United States House

The importance of contextual aspects in the care for patients with functional somatic symptoms

Functional somatic symptoms refer to physical symptoms that cannot be (bio) medically explained. The pattern or clustering of such symptoms may lead to functional syndromes like chronic fatigue syndrome, fibromyalgia, irritable bowel syndrome, among many others. Since the underlying pathophysiology remains unknown, several explanatory models have been proposed, nearly all including social and psychological parameters. These models have stimulated effectiveness studies of several psychological and psychopharmacological therapies. While the evidence for their effectiveness is steadily growing, effect-sizes are at most moderate and many patients do not benefit. We hypothesize that the context in which interventions for functional somatic symptoms are delivered substantially influences their effectiveness. Although this hypothesis is in line with explanatory models of functional somatic symptoms, to our knowledge, studies primarily focusing on the influence of contextual aspects on treatment outcome are scarce. Contextual research in the field of somatic symptoms has (irrespective whether these symptoms can be medically explained or not), however, just begun and already yielded some valuable results. These findings can be organized according to Duranti's and Goodwin's theoretical approach to context in order to substantiate our hypothesis. Based on this approach, we categorized empirical findings in three contextual aspects, i.e. 1) the setting, 2) the behavioural environment, and 3) the language environment. Collectively, some support is found for the fact that early identification of patients with functional somatic symptoms, starting treatment as soon as possible, having a neat appearance and an organized office interior, a warm and friendly nonverbal approach and a language use without defensiveness are contextual parameters which enhance the assessment by the patient of the physician's competence to help. Nonetheless, in vivo studies addressing the most aspects, i.e. nonverbal behaviour and language, are needed for better understanding of these contextual aspect. Moreover, future research should address to what extent optimizing contextual aspects improve care for functional somatic symptoms

A single point mutation in precursor protein VI doubles the mechanical strength of human adenovirus

Viruses are extensively studied as vectors for vaccine applications and gene therapies. For these applications, understanding the material properties of viruses is crucial for creating optimal functionality. Using atomic force microscopy (AFM) nanoindentation, we studied the mechanical properties of human adenovirus type 5 with the fiber of type 35 (Ad5F35) and compared it to viral capsids with a single point mutation in the protein VI precursor protein (pVI-S28C). Surprisingly, the pVI-S28C mutant turned out to be twice as stiff as the Ad5F35 capsids. We suggest that this major increase in strength is the result of the DNA crosslinking activity of precursor protein VII, as this protein was detected in the pVI-S28C mutant capsids. The infectivity was similar for both capsids, indicating that mutation did not affect the ability of protein VI to lyse the endosomal membrane. This study highlights that it is possible to increase the mechanical stability of a capsid even with a single point mutation while not affecting the viral life cycle. Such insight can help enable the development of more stable vectors for therapeutic applications

Exploring temporal relationships among worrying, anxiety, and somatic symptoms

OBJECTIVES: The role of anxiety symptoms in the development of functional somatic symptoms (FSS) is unknown. Somatic symptoms may be triggered by or give rise to anxiety symptoms. This study aimed to 1) explore interrelationships among within-day worrying, feeling anxious, and somatic symptoms, and 2) investigate the association between these interrelationships and overall level of FSS. METHODS: This study included 767 participants (83% females, mean age 39 years), who were recruited through an online crowdsourcing study in the Dutch general population. Somatic, and anxiety symptoms were reported thrice daily (6-h intervals) for 30 days using electronic diaries. FSS were assessed at baseline (PHQ-15). Temporal relationships among worrying, feeling anxious, and somatic symptoms were modeled using a multilevel vector autoregressive model. RESULTS: We observed large heterogeneity in the within-person interrelationships among worrying, feeling anxious and somatic symptoms. Averaged over participants, higher-than-usual somatic symptoms were associated with increases in levels of worrying six hours later (B = 0.017, 95% CI [0.006, 0.027]). At the between-person level, FSS levels predicted the persistence of feeling anxious (B = 0.230 95% CI [0.105, 0.350]) and the carry-over of worrying to feeling anxious over six-hours (B = 0.159, 95% CI [0.031, 0.283]). CONCLUSIONS: In contrast to what we expected, higher levels of somatic symptoms over multiple weeks were associated with the persistence and carry-over of within-day anxiety-related symptoms. One within-person association between psychological and somatic symptoms during the day was observed, suggesting that, over a time span of 6-h, anxiety symptoms relate to somatic symptoms only in a minority of people from the general population

The nature of love: Harlow, Bowlby and Bettelheim on affectionless mothers

Harry Harlow, famous for his experiments with rhesus monkeys and cloth and wire mothers, was visited by psychiatrist and psychoanalyst John Bowlby and by child psychologist Bruno Bettelheim in 1958. They made similar observations of Harlow’s monkeys, yet their interpretations were strikingly different. Bettelheim saw Harlow’s wire mother

Factors associated with Self Rated Health in persons with tinnitus from the general population

OBJECTIVES: Tinnitus, the perception of a sound without a corresponding external source, may be associated with decreased Self-Rated Health (SRH). Most research on tinnitus has been done in clinical populations. We aimed to study factors associated with SRH in individuals reporting tinnitus from the general population. METHODS: In this cross-sectional study, we used data of participants of the Lifelines population-based cohort who answered the question: "Do you hear soughing or whistling in your ear or ears?" (N=124,490). SRH was assessed using the RAND-36 item on SRH. Linear regression was used to study associations between SRH and impairment of hearing, physical and mental health, lifestyle, personality, and demographic features, in the group reporting always tinnitus (N=8,011). Models were also run in the entire study cohort, to test whether tinnitus was associated with SRH after adjustment for these variables. RESULTS: Of all participants, 6.4% reported always hearing tinnitus, with 83.7% of these reporting good to excellent SRH. The strongest positive associations with SRH in the group reporting always tinnitus were found for younger age, higher education levels, good sleep quality, more social contacts, absence of irritable bowel syndrome and fibromyalgia, high competence, and low impulsivity. In the total population, tinnitus was negatively associated with SRH, while adjusting for demographic features, physical and mental health history, lifestyle, and personality. CONCLUSION: Our findings contribute to increased understanding of resilience towards the negative consequences of tinnitus. In their early encounters with tinnitus patients, clinicians could focus on self-help regarding sleep hygiene and stimulate social activities

Childhood life events, immune activation and the development of mood and anxiety disorders:The TRAILS study

The experience of childhood life events is associated with higher vulnerability to develop psychiatric disorders. One of the pathways suggested to lead to this vulnerability is activation of the immune system. The aim of this study is to find out whether the association between childhood life events and the development of mood and anxiety disorders is predicted by the activation of the immune system. This study was performed in TRAILS, a large prospective population cohort, from which a subgroup was selected (N = 1084, 54.3% female, mean age 19.0 (s.d., 0.6)). Childhood life events before age 16 were assessed using questionnaires at age 12, 14, 16 and 19. Immune activation was assessed at age 16 by elevated high-sensitive C-reactive protein (hsCRP) and by levels of immunoglobulin G antibodies against the herpes viruses herpes simplex virus 1, cytomegalovirus and Epstein-Barr virus. At age 19, the presence of mood and anxiety disorders was determined using the World Health Organization Composite International Diagnostic Interview Version 3.0. Regression analyses were used to study the association between life events, the inflammatory markers and mental health. We found that childhood life events score was associated with risk of mood disorders (B = 0.269, Po0.001) and anxiety disorders (B = 0.129,