Ultrasonic NDE of Adhesive Bonds: The Inverse Problem

Over the past quarter century, a wide variety of ultrasonic techniques have been developed to determine the phase velocity and thickness of elastic plates. Techniques to measure the phase velocity include toneburst [1–4], separable pulse methods [5–7], and spectroscopy [8–11]. These classical methods require that the specimen be thick enough such that two successive echoes from the front and the back faces of the specimen, respectively, be separable in the time domain. Kinra and Dayal [12], developed a through transmission technique which removes this particular limitation of the classical methods. This technique works satisfactorily for the measurement of the phase velocity for specimens whose thickness is greater than one-half of the wavelength; for thinner specimens, however, their numerical algorithm runs into convergence problems. Moreover, their numerical algorithm cannot be used to determine thickness at any wavelength. The reasons for their convergence problems are discussed in detail by Iyer, Hanneman and Kinra [13]. They demonstrated that a detailed sensitivity analysis is a necessary pre-requisite for the development of a robust inversion algorithm. Accordingly, a new inversion scheme based on the method of least squares was developed by Iyer and Kinra to determine thickness from the measurements of phase, magnitude and complex spectrum, respectively, [14–17]. In all of the above ultrasonic methods only one parameter can be determined i.e., an accurate knowledge of thickness is required to determine the wavespeed and vice versa. This defines the central objective of the present work: In this paper we present a technique for determining, simultaneously, the thickness and wavespeed of a thin layer

Capitate and hamate fracture in a child: the value of MRI imaging

Carpal bone fractures in children are rare, and little is known about the appropriate tools to diagnose them, particularly in toddlers. We present a 2-year-old child with a capitate and hamate fracture. Based on our experiences with this case and on a review of the literature, we discuss the value of magnetic resonance imaging in carpal trauma in children

Importance of basophil activation testing in insect venom allergy

<p>Abstract</p> <p>Background</p> <p>Venom immunotherapy (VIT) is the only effective treatment for prevention of serious allergic reactions to bee and wasp stings in sensitized individuals. However, there are still many questions and controversies regarding immunotherapy, like selection of the appropriate allergen, safety and long term efficacy.</p> <p>Methods</p> <p>Literature review was performed to address the role of basophil activation test (BAT) in diagnosis of venom allergy.</p> <p>Results</p> <p>In patients with positive skin tests or specific IgE to both honeybee and wasp venom, IgE inhibition test can identify sensitizing allergen only in around 15% and basophil activation test increases the identification rate to around one third of double positive patients. BAT is also diagnostic in majority of patients with systemic reactions after insect stings and no detectable IgE. High basophil sensitivity to allergen is associated with a risk of side effects during VIT. Persistence of high basophil sensitivity also predicts a treatment failure of VIT.</p> <p>Conclusion</p> <p>BAT is a useful tool for better selection of allergen for immunotherapy, for identification of patients prone to side effects and patients who might be treatment failures. However, long term studies are needed to evaluate the accuracy of the test.</p

Stress from Uncertainty from Graduation to Retirement—A Population-Based Study of Swiss Physicians

BACKGROUND: Uncertainty shapes many decisions made by physicians everyday. Uncertainty and physicians’ inability to handle it may result in substandard care and unexplained variations in patterns of care. OBJECTIVE: To describe socio-demographic and professional characteristics of reactions to uncertainty among physicians from all specialties, including physicians in training. DESIGN: Cross-sectional postal survey. PARTICIPANT: All physicians practicing in Geneva, Switzerland (n = 1,994). MEASUREMENT: Reaction to medical care uncertainty was measured with the Anxiety Due to Uncertainty and Concern About Bad Outcomes scales. The questionnaire also included items about professional characteristics and work-related satisfaction scales. RESULTS: After the first mailing and two reminders, 1,184 physicians responded to the survey. In univariate analysis, women, junior physicians, surgical specialists, generalist physicians, and physicians with lower workloads had higher scores in both scales. In multivariate models, sex, medical specialty, and workload remained significantly associated with both scales, whereas clinical experience remained associated only with concern about bad outcomes. Higher levels of anxiety due to uncertainty were associated with lower scores of work-related satisfaction, while higher levels of concern about bad outcomes were associated with lower satisfaction scores for patient care, personal rewards, professional relations, and general satisfaction, but not for work-related burden or satisfaction with income-prestige. The negative effect of anxiety due to uncertainty on work-related satisfaction was more important for physicians in training. CONCLUSION: Physicians’ reactions to uncertainty in medical care were associated with several dimensions of work-related satisfaction. Physicians in training experienced the greatest impact of anxiety due to uncertainty on their work-related satisfaction. Incorporating strategies to deal with uncertainty into residency training may be useful

Cognitive vision system for control of dexterous prosthetic hands: Experimental evaluation

<p>Abstract</p> <p>Background</p> <p>Dexterous prosthetic hands that were developed recently, such as SmartHand and i-LIMB, are highly sophisticated; they have individually controllable fingers and the thumb that is able to abduct/adduct. This flexibility allows implementation of many different grasping strategies, but also requires new control algorithms that can exploit the many degrees of freedom available. The current study presents and tests the operation of a new control method for dexterous prosthetic hands.</p> <p>Methods</p> <p>The central component of the proposed method is an autonomous controller comprising a vision system with rule-based reasoning mounted on a dexterous hand (CyberHand). The controller, termed cognitive vision system (CVS), mimics biological control and generates commands for prehension. The CVS was integrated into a hierarchical control structure: 1) the user triggers the system and controls the orientation of the hand; 2) a high-level controller automatically selects the grasp type and size; and 3) an embedded hand controller implements the selected grasp using closed-loop position/force control. The operation of the control system was tested in 13 healthy subjects who used Cyberhand, attached to the forearm, to grasp and transport 18 objects placed at two different distances.</p> <p>Results</p> <p>The system correctly estimated grasp type and size (nine commands in total) in about 84% of the trials. In an additional 6% of the trials, the grasp type and/or size were different from the optimal ones, but they were still good enough for the grasp to be successful. If the control task was simplified by decreasing the number of possible commands, the classification accuracy increased (e.g., 93% for guessing the grasp type only).</p> <p>Conclusions</p> <p>The original outcome of this research is a novel controller empowered by vision and reasoning and capable of high-level analysis (i.e., determining object properties) and autonomous decision making (i.e., selecting the grasp type and size). The automatic control eases the burden from the user and, as a result, the user can concentrate on what he/she does, not on how he/she should do it. The tests showed that the performance of the controller was satisfactory and that the users were able to operate the system with minimal prior training.</p

Palaeoclimatic events, dispersal and migratory losses along the Afro-European axis as drivers of biogeographic distribution in Sylvia warblers

<p>Abstract</p> <p>Background</p> <p>The Old World warbler genus <it>Sylvia </it>has been used extensively as a model system in a variety of ecological, genetic, and morphological studies. The genus is comprised of about 25 species, and 70% of these species have distributions at or near the Mediterranean Sea. This distribution pattern suggests a possible role for the Messinian Salinity Crisis (from 5.96-5.33 Ma) as a driving force in lineage diversification. Other species distributions suggest that Late Miocene to Pliocene Afro-tropical forest dynamics have also been important in the evolution of <it>Sylvia </it>lineages. Using a molecular phylogenetic hypothesis and other methods, we seek to develop a biogeographic hypothesis for <it>Sylvia </it>and to explicitly assess the roles of these climate-driven events.</p> <p>Results</p> <p>We present the first strongly supported molecular phylogeny for <it>Sylvia</it>. With one exception, species fall into one of three strongly supported clades: one small clade of species distributed mainly in Africa and Europe, one large clade of species distributed mainly in Africa and Asia, and another large clade with primarily a circum-Mediterranean distribution. Asia is reconstructed as the ancestral area for <it>Sylvia</it>. Long-distance migration is reconstructed as the ancestral character state for the genus, and sedentary behavior subsequently evolved seven times.</p> <p>Conclusion</p> <p>Molecular clock calibration suggests that <it>Sylvia </it>arose in the early Miocene and diverged into three main clades by 12.6 Ma. Divergence estimates indicate that the Messinian Salinity Crisis had a minor impact on <it>Sylvia</it>. Instead, over-water dispersals, repeated loss of long-distance migration, and palaeo-climatic events in Africa played primary roles in <it>Sylvia </it>divergence and distribution.</p

What is psychiatry? Co-producing complexity in mental health

What is psychiatry? Such a question is increasingly important to engage with in light of the development of new diagnostic frameworks that have wide-ranging and international clinical and societal implications. I suggest in this reflective essay that ‘psychiatry' is not a singular entity that enjoins consistent forms of critique along familiar axes; rather, it is a heterogeneous assemblage of interacting material and symbolic elements (some of which endure, and some of which are subject to innovation). In underscoring the diversity of psychiatry, I seek to move towards further sociological purchase on what remains a contested and influential set of discourses and practices. This approach foregrounds the relationships between scientific knowledge, biomedical institutions, social action and subjective experience; these articulations co-produce both psychiatry and each other. One corollary of this emphasis on multiplicity and incoherence within psychiatric theory, research and practice, is that critiques which elide this complexity are rendered problematic. Engagements with psychiatry are, I argue, best furthered by recognising its multifaceted nature

The effects of long-term total parenteral nutrition on gut mucosal immunity in children with short bowel syndrome: a systematic review

BACKGROUND: Short bowel syndrome (SBS) is defined as the malabsorptive state that often follows massive resection of the small intestine. Most cases originate in the newborn period and result from congenital anomalies. It is associated with a high morbidity, is potentially lethal and often requires months, sometimes years, in the hospital and home on total parenteral nutrition (TPN). Long-term survival without parenteral nutrition depends upon establishing enteral nutrition and the process of intestinal adaptation through which the remaining small bowel gradually increases its absorptive capacity. The purpose of this article is to perform a descriptive systematic review of the published articles on the effects of TPN on the intestinal immune system investigating whether long-term TPN induces bacterial translocation, decreases secretory immunoglobulin A (S-IgA), impairs intestinal immunity, and changes mucosal architecture in children with SBS. METHODS: The databases of OVID, such as MEDLINE and CINAHL, Cochran Library, and Evidence-Based Medicine were searched for articles published from 1990 to 2001. Search terms were total parenteral nutrition, children, bacterial translocation, small bowel syndrome, short gut syndrome, intestinal immunity, gut permeability, sepsis, hyperglycemia, immunonutrition, glutamine, enteral tube feeding, and systematic reviews. The goal was to include all clinical studies conducted in children directly addressing the effects of TPN on gut immunity. RESULTS: A total of 13 studies were identified. These 13 studies included a total of 414 infants and children between the ages approximately 4 months to 17 years old, and 16 healthy adults as controls; and they varied in design and were conducted in several disciplines. The results were integrated into common themes. Five themes were identified: 1) sepsis, 2) impaired immune functions: In vitro studies, 3) mortality, 4) villous atrophy, 5) duration of dependency on TPN after bowel resection. CONCLUSION: Based on this exhaustive literature review, there is no direct evidence suggesting that TPN promotes bacterial overgrowth, impairs neutrophil functions, inhibits blood's bactericidal effect, causes villous atrophy, or causes to death in human model. The hypothesis relating negative effects of TPN on gut immunity remains attractive, but unproven. Enteral nutrition is cheaper, but no safer than TPN. Based on the current evidence, TPN seems to be safe and a life saving solution