Sensitivity to social exclusion in major depressive disorder (MDD) predicts therapeutic outcome after in-patient treatment

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Biological control of whitefly on Gerbera: success or failure? : tritrophic interactions between Gerbera jamesonii, Trialeurodes vaporariorum and Encarsia formosa

In this thesis fundamental and applied research is described that was initiated to develop biological control of whitefly with the parasitoid Encarsia formosa in the ornamental Gerbera jamesonii Hook (Campanulales: Compositae).To test the hypothesis that host plant architecture of G. jamesonii results in a different whitefly distribution pattern when compared with vegetables such as tomato and cucumber, we started studying whitefly dispersal behaviour and the choice of oviposition and feeding sites of the greenhouse whitefly within a plant. The behaviour of the herbivore was compared on two cultivars of G. jamesonii , differing in hairiness.The dispersal process of whiteflies was directed to the centre of the plant. This leads to adult and egg aggregation on young leaves on the hairy as well as on the less-hairy cultivar. Three parameters (development time, mortality and fecundity) to measure performance of T. vaporariorum were investigated, to determine a possible link with preference for certain leaves or cultivars by whitefly adults. Development duration of immatures is the same on leaves of different ages. Mortality of whiteflies is much lower and fecundity is higher on young Gerbera leaves. The dispersal and aggregation of whitefly adults between plants was investigated next. Whitefly populations were strongly aggregated on Gerbera , which seems typical for this whitefly species. Travel distance and dispersal speed were similar on very different crops such as Gerbera and tomato. Leaf selection behaviour and the resulting distribution of greenhouse whitefly on Gerbera was similar to that on vegetables. The first hypothesis that differences in host plant architecture result in different whitefly distributions is, thus, rejected.The second hypothesis that plant characteristics such as shape and leaf hairiness of G. jamesonii negatively influence the searching behaviour of the parasitoid E. formosa was tested next. Trichome density of Gerbera cultivars appeared to influence the walking behaviour (walking speed, walking activity and straightness of walkng path) and searching efficiency of E. formosa only slightly. Gerbera leaves of all age classes were found and searched by the parasitoid. Number of landings was the same on infested and uninfested Gerbera leaves; parasitoids were observed more often on the abaxial side of the leaves, where hosts are found normally. The foraging behaviour of E. formosa on leaves of a range of Gerbera cultivars is comparable. The searching efficiency of E. formosa on Gerbera is as good as on the vegetable tomato, so also the second hypothesis that plant characteristics negatively influence the searching behaviour of Encarsia on Gerbera , is rejected.The third hypothesis that plant architecture and leaf characteristics of G. jamesonii lead to failure of whitefly biological control on Gerbera was tested in glasshouses. Glasshouse studies are essential to validate the conclusions based on small population experiments and laboratory experiments. One central release of on average three parasitoids per plant, three weeks after whitefly introduction resulted in successful pest control in a small glasshouse of 60 m 2 . Sufficient control was not achieved in a larger glasshouse (300 m 2 ).Possible explanations for the failure of biological control in Gerbera were evaluated with a simulation model of G. jamesonii , T. vaporariorum and E. formosa . Surprisingly, and as a result of integrating all parameters for crop, pest, natural enemy and glasshouse temperature, we found that it is mainly the glasshouse temperature that determines success or failure of biological control in Gerbera .With an adjustment of the release strategy of parasitoids, the right choice of (partially) resistant Gerbera cultivars, and a slight increase of glasshouse temperature in early spring, biological control of T. vaporariorum on G. jamesonii will be successful.</p

Rumination and Age: Some Things Get Better

Rumination has been defined as a mode of responding to distress that involves passively focusing one's attention on symptoms of distress without taking action. This dysfunctional response style intensifies depressed mood, impairs interpersonal problem solving, and leads to more pessimistic future perspectives and less social support. As most of these results were obtained from younger people, it remains unclear how age affects ruminative thinking. Three hundred members of the general public ranging in age from 15 to 87 years were asked about their ruminative styles using the Response Styles Questionnaire (RSQ), depression and satisfaction with life. A Mokken Scale analysis confirmed the two-factor structure of the RSQ with brooding and reflective pondering as subcomponents of rumination. Older participants (63 years and older) reported less ruminative thinking than other age groups. Life satisfaction was associated with brooding and highest for the earlier and latest life stages investigated in this study

A Multilevel Investigation of Resiliency Scales for Children and Adolescents: The Relationships Between Self-Perceived Emotion Regulation, Vagally Mediated Heart Rate Variability, and Personal Factors Associated With Resilience

Personal resiliency refers to individual attributes that are related to the process of successfully adapting to the environment in the face of adverse conditions, also known as resilience. Emotion regulation is increasingly found as a core component in mental health and found to modulate individual differences in the management of emotional responses. The Resiliency Scales for Children and Adolescents (RSCA; Prince-Embury, 2006, 2007) were designed to systematically identify and quantify core personal qualities of resiliency in youth, and includes Sense of Mastery scale (MAS), Sense of Relatedness scale (REL), and Emotional Reactivity (REA) scale. The following study was first conducted to confirm the Three-Factor model of Personal Resiliency in a Norwegian student sample using factor analytic procedures. Secondly and the main purpose of the study, was to investigate if personal resiliency is associated with self-reported measures related to emotion regulation, and with resting vagally mediated heart rate variability (vmHRV) as a psychophysiological index of emotion regulation capacity. A revised scale adapted to the Norwegian sample was developed. Results indicate that protective indices related to personal resiliency are associated with both self-reported adaptive emotion regulation and outcome, and partly related to high capacity for emotion regulation indicated by vmHRV. Risk related to personal vulnerability was associated with maladaptive emotion regulation and outcome, but was not associated with emotion regulation capacity. Together the findings provide supporting evidence of both self-reported and psychophysiological correlates between emotion regulatory processes and personal resiliency indicated by RSCA

The association between work-related rumination and heart rate variability: A field study

This is the final version. Available on open access from Frontiers Media via the DOI in this recordThe objective of this study was to examine the association between perseverative cognition in the form of work-related rumination, and heart rate variability (HRV). We tested the hypothesis that high ruminators would show lower vagally mediated HRV relative to low ruminators during their leisure time. Individuals were classified as being low (n = 17) or high ruminators (n = 19), using the affective scale on the work-related rumination measure. HRV was assessed using a wrist sensor band (Microsoft Band 2). HRV was sampled between 8 pm and 10 pm over three workday evenings (Monday to Wednesday) while individuals carried out their normal evening routines. Compared to the low ruminators, high affective ruminators demonstrated lower HRV in the form of root mean square successive differences (RMSSDs), relative to the low ruminators, indicating lower parasympathetic activity. There was no significant difference in heart rate, or activity levels between the two groups during the recording periods. The current findings of this study may have implications for the design and delivery of interventions to help individuals unwind post work and to manage stress more effectively. Limitations and implications for future research are discussed

Investigation of Vacuum Arc Anode Temperatures of Cu-Cr and Pure Cu Contacts

The present contribution reports on investigations of electrode temperatures for pure Cu electrodes and Cu–Cr electrodes of different diameters exposed to vacuum arcs with sinusoidal currents of 5-15 kA and an axial magnetic field up to 180 mT. It is found that surface temperatures of pure Cu electrodes are significantly lower than for Cu–Cr electrodes of the same diameter. This must be explained by different thermal properties of both materials. Reducing the diameter of Cu–Cr electrodes it is found that surface temperatures increase, but moreover it is shown that the enthalpy stored in the electrode bulk material may effect electrode temperatures on timescales much longer than the current pulse width, particularly if there is no effective heat dissipation after current zero

Photometric properties of resolved and unresolved magnetic elements

We investigate the photometric signature of magnetic flux tubes in the solar photosphere. We developed two dimensional, static numerical models of isolated and clustered magnetic flux tubes. We investigated the emergent intensity profiles at different lines-of-sight for various spatial resolutions and opacity models. We found that both geometric and photometric properties of bright magnetic features are determined not only by the physical properties of the tube and its surroundings, but also by the particularities of the observations, including the line/continuum formation height, the spatial resolution and the image analyses techniques applied. We show that some observational results presented in the literature can be interpreted by considering bright magnetic features to be clusters of smaller elements, rather than a monolithic flux tube.Comment: 12 page

Vertical pairing of identical particles suspended in the plasma sheath

It is shown experimentally that vertical pairing of two identical microspheres suspended in the sheath of a radio-frequency (rf) discharge at low gas pressures (a few Pa), appears at a well defined instability threshold of the rf power. The transition is reversible, but with significant hysteresis on the second stage. A simple model, which uses measured microsphere resonance frequencies and takes into account besides Coulomb interaction between negatively charged microspheres also their interaction with positive ion wake charges, seems to explain the instability threshold quite well.Comment: 4 pages, 6 figures. to appear in Phys. Rev. Lett. 86, May 14th (2001

A rare case of abnormal uterine bleeding caused by cavernous hemangioma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Cavernous hemangiomas of the uterus are extremely rare, benign lesions. A survey of the current literature identified fewer than 50 cases of hemangioma of the uterus.</p> <p>Case presentation</p> <p>We report a case of cavernous hemangioma of the uterus in a 27-year-old Malay, para 1 woman who presented at our hospital with torrential vaginal bleeding having been transferred by land ambulance from a district hospital 30 minutes away. 11 weeks previously she had an urgent cesarean section at our hospital. She had to undergo a hysterectomy to control her bleeding after other measures were unsuccessful. A histopathological report confirmed a diffuse ramifying hemangioma of the cervix and uterus with left hematosalpinx.</p> <p>Conclusion</p> <p>Most ramifying hemangioma lesions are asymptomatic and are found incidentally, but sometimes they may cause abnormal vaginal bleeding and hence should be included in the differential diagnosis of patients with vaginal bleeding. Hysterectomy is the primary mode of treatment in most symptomatic cases.</p

A Multilevel Investigation of Resiliency Scales for Children and Adolescents: The Relationships Between Self-Perceived Emotion Regulation, Vagally Mediated Heart Rate Variability, and Personal Factors Associated with Resilience

Personal resiliency refers to individual attributes that are related to the process of successfully adapting to the environment in the face of adverse conditions, also known as resilience. Emotion regulation is increasingly found as a core component in mental health and found to modulate individual differences in the management of emotional responses. The Resiliency Scales for Children and Adolescents (RSCA; Prince-Embury, 2006, 2007) were designed to systematically identify and quantify core personal qualities of resiliency in youth, and includes Sense of Mastery scale (MAS), Sense of Relatedness scale (REL), and Emotional Reactivity (REA) scale. The following study was first conducted to confirm the Three-Factor model of Personal Resiliency in a Norwegian student sample using factor analytic procedures. Secondly and the main purpose of the study, was to investigate if personal resiliency is associated with self-reported measures related to emotion regulation, and with resting vagally mediated heart rate variability (vmHRV) as a psychophysiological index of emotion regulation capacity. A revised scale adapted to the Norwegian sample was developed. Results indicate that protective indices related to personal resiliency are associated with both self-reported adaptive emotion regulation and outcome, and partly related to high capacity for emotion regulation indicated by vmHRV. Risk related to personal vulnerability was associated with maladaptive emotion regulation and outcome, but was not associated with emotion regulation capacity. Together the findings provide supporting evidence of both self-reported and psychophysiological correlates between emotion regulatory processes and personal resiliency indicated by RSCA.publishedVersio