66 research outputs found
DNA barcoding and a precise morphological comparison revealed a cryptic species in the Nippolachnus piri complex (Hemiptera: Aphididae: Lachninae)
Nippolachnus is a small Palaearctic-Oriental genus of very characteristic aphids that live on the leaves of woody Rosaceae. One species, N. piri, has hitherto been regarded to be widely distributed and relatively polyphagous. Members of this genus are considered to be easy to recognize due to the absence of the ocular tubercle and triommatidia on the head. We conducted research on the morphology and generic characters of Nippolachnus piri complex using scanning electron microscopy (for the first time) and DNA barcoding. We analyzed N. piri populations on Pyrus and other plants (Eriobotrya, Rhaphiolepis and Sorbus) in Japan and the Republic of Korea. Specifically, a high genetic divergence value was found between the N. piri populations associated with different host plants. SEM investigation of the head capsule revealed that a triommatidium is present under the compound eye, despite their lack of an ocular tubercle. We propose Nippolachnus micromeli Shinji, 1924 stat. nov. as a cryptic species in the N. piri complex based on a morphological comparison, DNA barcoding and different host-plant associations. Illustrations and descriptions of studied species are given. Morphological keys to the apterae and alatae of all known species of the genus Nippolachnus are also provided
Orthorexic tendencies are linked with difficulties with emotion identification and regulation.
Background: Orthorexia nervosa (ON) is characterised by an unhealthy obsession with healthy eating and while it is not recognised as an eating disorder (or any disorder), current research is exploring similarities and differences with such disorders. The literature has shown that individuals with eating disorders have difficulties identifying and describing emotions (known as alexithymia) as well as regulating them. However no research to date has looked at whether people with orthorexic tendencies also suffer from difficulties with emotions. In this paper, we refer to people with orthorexic tendencies but do not assume that their healthy eating is at a pathological level needing clinical attention. Methods: The current study examined this by asking 196 healthy adults with an interest in healthy eating to complete four questionnaires to measure ON (ORTO-15 - reduced to ORTO-7CS), eating psychopathology (EAT-26), alexithymia (TAS-20) and emotion dysregulation (DERS-16). Results: We found that difficulties identifying and regulating emotions was associated with symptoms of ON, similar to what is found in other eating disorders. We suggest that ON behaviours may be used as a coping strategy in order to feel in control in these participants who have poor emotion regulation abilities. Conclusions: Our results show that individuals with ON tendencies may share similar difficulties with emotions compared to other eating disorders. While important, our results are limited by the way we measured ON behaviours and we recommend that further research replicate our findings once a better and more specific tool is developed and validated to screen for ON characteristics more accurately
A Geometric terrain methodology for global optimization
Global optimization remains an important area of active research. Many macroscopic and microscopic applications in science and engineering still present formidable challenges to current global optimization techniques. In this work, a completely different, novel and general geometric framework for continuous global optimization is described. The proposed methodology is based on intelligent movement along the valleys and ridges of an appropriate objective function using downhill, local minimization calculations defined in terms of a trust region method and uphill integration of the Newton-like vector field combined with intermittent SQP corrector steps. The novel features of the proposed methodology include new rigorous mathematical definitions of valleys and ridges, the combined use of objective function and gradient surfaces to guide movement, and techniques to assist both exploration and termination. Collisions with boundaries of the feasible region, integral curve bifurcations, and the presence of non-differentiabilities are also discussed. A variety of examples are used to make key concepts clear and to demonstrate the reliability, efficiency and robustness of terrain methods for global optimization
Funneling algorithms multiscale optimization on rugged terrains
Global optimization problems for which it is either intractable or undesirable to find all stationary points and that contain so-called rough or rugged objective function landscapes are studied. Such problems often show considerable differences between the small-scale (or local) geometry and the large-scale (or more global) geometry. A new class of functions called generalized exponential funnel functions is proposed for modeling large-scale geometry. This class of functions is capable of modeling folds, cups, cones, funnels, and other geometric objects that recur in many physical applications. The basic mathematics of exponential funnels is described, along with their numerical and algorithmic implications. It is shown that funnels provide a nonconvex model of large-scale geometry that, when approximated correctly, exhibits a unique and easily calculated minimum that can be estimated from a small amount of local objective-function and derivative information. Ways of extracting average gradient and Hessian matrix information are presented, and novel interpolating formulas for building funnel approximations of large-scale geometries are given. A funneling algorithm, intended to guide or funnel iterates to regions where the most promising global optimizers are expected to lie, is described. A multiscale global optimization algorithm based on the combined use of terrain methods and funneling algorithms is proposed. The terrain methodology is used to gather small-scale information while a funneling algorithm is used to guide the overall optimization calculations and to make large moves within the feasible region. Communication between scales is also addressed. Typical empirical force field functionality, many stationary points, and changes in convexity are used to clearly illustrate by example, but not to prove theoretically, that the combined terrain/funneling methodology is capable of finding a global minimum without calculating all stationary points and can lead to significant reductions in overall computational work
Digitalizing a Brief Intervention to Reduce Intrusive Memories of Psychological Trauma : Qualitative Interview Study
Background: The COVID-19 pandemic has escalated the global need for remotely delivered and scalable interventions after psychological trauma. A brief intervention involving a computer game as an imagery-competing task has shown promising results for reducing the number of intrusive memories of trauma—one of the core clinical symptoms of posttraumatic stress disorder. To date, the intervention has only been delivered face-to-face. To be tested and implemented on a wider scale, digital adaptation for remote delivery is crucial. An important first step is to develop digitalized intervention materials in a systematic way based on feedback from clinicians, researchers, and students in preparation for pilot testing with target users. Objective: The first aim of this study is to obtain and analyze qualitative feedback on digital intervention materials, namely two animated videos and two quizzes that explain the target clinical symptoms and provide intervention instructions. The second aim is to refine the digitalized materials based on this feedback. Methods: We conducted semistructured interviews with 12 participants who had delivered or had knowledge of the intervention when delivered face-to-face. We obtained in-depth feedback on the perceived feasibility of using the digitalized materials and suggestions for improvements. Interviews were assessed using qualitative content analysis, and suggested improvements were evaluated for implementation using a systematic method of prioritization. Results: A total of three overarching themes were identified from the data. First, participants were highly positive about the potential benefits of using these digital materials for remote delivery, reporting that the videos effectively conveyed key concepts of the symptom and its treatment. Second, some modifications to the materials were suggested for improving clarity. On the basis of this feedback, we made nine specific changes. Finally, participants raised some key challenges for remote delivery, mainly in overcoming the lack of real-time communication during the intervention. Conclusions: Clinicians, researchers, and clinical psychology students were overall confident in the use of digitalized materials to remotely deliver a brief intervention to reduce intrusive memories of trauma. Guided by participant feedback, we identified and implemented changes to refine the intervention materials. This study lays the groundwork for the next step: pilot testing remote delivery of the full intervention to trauma survivors.De två första författarna delar förstaförfattarskapet</p
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