Generalized expansion of nociceptive reflex receptive fields in chronic pain patients

Widespread central hypersensitivity is present in chronic pain and contributes to pain and disability. According to animal studies, expansion of receptive fields of spinal cord neurons is involved in central hypersensitivity. We recently developed a method to quantify nociceptive receptive fields in humans using spinal withdrawal reflexes. Here we hypothesized that patients with chronic pelvic pain display enlarged reflex receptive fields. Secondary endpoints were subjective pain thresholds and nociceptive withdrawal reflex thresholds after single and repeated (temporal summation) electrical stimulation. 20 patients and 25 pain-free subjects were tested. Electrical stimuli were applied to 10 sites on the foot sole for evoking reflexes in the tibialis anterior muscle. The reflex receptive field was defined as the area of the foot (fraction of the foot sole) from which a muscle contraction was evoked. For the secondary endpoints, the stimuli were applied to the cutaneous innervation area of the sural nerve. Medians (25-75 percentiles) of fraction of the foot sole in patients and controls were 0.48 (0.38-0.54) and 0.33 (0.27-0.39), respectively (P=0.008). Pain and reflex thresholds after sural nerve stimulation were significantly lower in patients than in controls (P<0.001 for all measurements). This study provides for the first time evidence for widespread expansion of reflex receptive fields in chronic pain patients. It thereby identifies a mechanism involved in central hypersensitivity in human chronic pain. Reverting the expansion of nociceptive receptive fields and exploring the prognostic meaning of this phenomenon may become future targets of clinical research.

ASSESSING THE UNRELIABILITY OF THE MEDICAL LITERATURE: A RESPONSE TO "WHY MOST PUBLISHED RESEARCH FINDINGS ARE FALSE"

A recent article in this journal (Ioannidis JP (2005) Why most published research findings are false. PLoS Med 2: e124) argued that more than half of published research findings in the medical literature are false. In this commentary, we examine the structure of that argument, and show that it has three basic components: 1)An assumption that the prior probability of most hypotheses explored in medical research is below 50%. 2)Dichotomization of P-values at the 0.05 level and introduction of a “bias” factor (produced by significance-seeking), the combination of which severely weakens the evidence provided by every design. 3)Use of Bayes theorem to show that, in the face of weak evidence, hypotheses with low prior probabilities cannot have posterior probabilities over 50%. Thus, the claim is based on a priori assumptions that most tested hypotheses are likely to be false, and then the inferential model used makes it impossible for evidence from any study to overcome this handicap. We focus largely on step (2), explaining how the combination of dichotomization and “bias” dilutes experimental evidence, and showing how this dilution leads inevitably to the stated conclusion. We also demonstrate a fallacy in another important component of the argument –that papers in “hot” fields are more likely to produce false findings. We agree with the paper’s conclusions and recommendations that many medical research findings are less definitive than readers suspect, that P-values are widely misinterpreted, that bias of various forms is widespread, that multiple approaches are needed to prevent the literature from being systematically biased and the need for more data on the prevalence of false claims. But calculating the unreliability of the medical research literature, in whole or in part, requires more empirical evidence and different inferential models than were used. The claim that “most research findings are false for most research designs and for most fields” must be considered as yet unproven.

Exposure modeling of high-frequency electromagnetic fields

We developed a geospatial model that calculates ambient high-frequency electromagnetic field (HF-EMF) strengths of stationary transmission installations such as mobile phone base stations and broadcast transmitters with high spatial resolution in the order of 1 m. The model considers the location and transmission patterns of the transmitters, the three-dimensional topography, and shielding effects by buildings. The aim of the present study was to assess the suitability of the model for exposure monitoring and for epidemiological research. We modeled time-averaged HF-EMF strengths for an urban area in the city of Basel as well as for a rural area (Bubendorf). To compare modeling with measurements, we selected 20 outdoor measurement sites in Basel and 18 sites in Bubendorf. We calculated Pearson's correlation coefficients between modeling and measurements. Chance-corrected agreement was evaluated by weighted Cohen's kappa statistics for three exposure categories. Correlation between measurements and modeling of the total HF-EMF strength was 0.67 (95% confidence interval (CI): 0.33-0.86) in the city of Basel and 0.77 (95% CI: 0.46-0.91) in the rural area. In both regions, kappa coefficients between measurements and modeling were 0.63 and 0.77 for the total HF-EMF strengths and for all mobile phone frequency bands. First evaluation of our geospatial model yielded substantial agreement between modeling and measurements. However, before the model can be applied for future epidemiologic research, additional validation studies focusing on indoor values are needed to improve model validity.Journal of Exposure Science and Environmental Epidemiology (2008) 18, 183-191; doi:10.1038/sj.jes.7500575; published online 4 April 2007.

ANALYSIS AND VISUALIZATION OF FLOW FIELDS USING INFORMATION-THEORETIC TECHNIQUES AND GRAPH-BASED REPRESENTATIONS

Three-dimensional flow visualization plays an essential role in many areas of science and engineering, such as aero- and hydro-dynamical systems which dominate various physical and natural phenomena. For popular methods such as the streamline visualization to be effective, they should capture the underlying flow features while facilitating user observation and understanding of the flow field in a clear manner. My research mainly focuses on the analysis and visualization of flow fields using various techniques, e.g. information-theoretic techniques and graph-based representations. Since the streamline visualization is a popular technique in flow field visualization, how to select good streamlines to capture flow patterns and how to pick good viewpoints to observe flow fields become critical. We treat streamline selection and viewpoint selection as symmetric problems and solve them simultaneously using the dual information channel [81]. To the best of my knowledge, this is the first attempt in flow visualization to combine these two selection problems in a unified approach. This work selects streamline in a view-independent manner and the selected streamlines will not change for all viewpoints. My another work [56] uses an information-theoretic approach to evaluate the importance of each streamline under various sample viewpoints and presents a solution for view-dependent streamline selection that guarantees coherent streamline update when the view changes gradually. When projecting 3D streamlines to 2D images for viewing, occlusion and clutter become inevitable. To address this challenge, we design FlowGraph [57, 58], a novel compound graph representation that organizes field line clusters and spatiotemporal regions hierarchically for occlusion-free and controllable visual exploration. We enable observation and exploration of the relationships among field line clusters, spatiotemporal regions and their interconnection in the transformed space. Most viewpoint selection methods only consider the external viewpoints outside of the flow field. This will not convey a clear observation when the flow field is clutter on the boundary side. Therefore, we propose a new way to explore flow fields by selecting several internal viewpoints around the flow features inside of the flow field and then generating a B-Spline curve path traversing these viewpoints to provide users with closeup views of the flow field for detailed observation of hidden or occluded internal flow features [54]. This work is also extended to deal with unsteady flow fields. Besides flow field visualization, some other topics relevant to visualization also attract my attention. In iGraph [31], we leverage a distributed system along with a tiled display wall to provide users with high-resolution visual analytics of big image and text collections in real time. Developing pedagogical visualization tools forms my other research focus. Since most cryptography algorithms use sophisticated mathematics, it is difficult for beginners to understand both what the algorithm does and how the algorithm does that. Therefore, we develop a set of visualization tools to provide users with an intuitive way to learn and understand these algorithms.

RESILIENT WOMEN, METISTIC SCIENTISTS: A MULTIPLE CASE STUDY OF HOW WOMEN NEGOTIATE THEIR SITUATEDNESS IN SCIENCE FIELDS

The concept of feminist metistic resilience postulates that the voiceless, the marginalized and the minority in societies employ strategies in order to turn tables in their favor. This study presents a qualitative analysis of how women, considered to be the minority, negotiate their situatedness in science fields in order to effect change in their lives or that of the society and why they become successful. By “situatedness,” I refer to the everyday life of women as they live and encounter people, society and culture, especially, the life of women who have transcended the culturally stipulated role of women and are excelling in a male dominated field. The study, in different dimensions, conceptualizes the reason for the fewer number of women in science; looks at how scientific methods and practices inhibit the development of women in science; and, finally, interrogates the question of objectivity in science. It becomes apparent, through feminist metistic resilience, that women become successful when they accept conventional practices in scientific arrangements and structures. They accept the practices by embracing and not questioning structures and arrangements that have shaped the field of science and by shifting shapes and assuming different forms in order to adapt to conditions they encounter. Apart from adapting and shape shifting, the women also become successful through environmental and social influences. My analysis suggests that more women can be encouraged to pursue science when women practicing science begin to question structures and arrangements that have shaped the practice of science over the centuries. The overall findings of the research provide implications for policy makers, educators and feminist researchers.

Applications of Stable Isotope Ratio Analysis for Social Science Research

Stable Isotope Ratio Analysis (SIRA) is the measurement of variation in different isotopes of same elements in a material. This technique is well-established in the natural sciences and has been long part of the methodological arsenal in fields such as geology and biology. More recently this technique has begun to be utilized in the social sciences, moving from initial applications in anthropology to potential uses in geography, public health, forensic science, and others. This presentation will discuss the techniques behind SIRA, examples of current applications in the natural and social sciences, and potential avenues of future research.

Temporal and spatial variability of personal exposure to radio frequency electromagnetic fields

BACKGROUND: Little is known about the population's exposure to radio frequency electromagnetic fields (RF-EMF) in industrialized countries. OBJECTIVES: To examine levels of exposure and the importance of different RF-EMF sources and settings in a sample of volunteers living in a Swiss city. METHODS: RF-EMF exposure of 166 volunteers from Basel, Switzerland, was measured with personal exposure meters (exposimeters). Participants carried an exposimeter for 1 week (two separate weeks in 32 participants) and completed an activity diary. Mean values were calculated using the robust regression on order statistics (ROS) method. RESULTS: Mean weekly exposure to all RF-EMF sources was 0.13 mW/m(2) (0.22 V/m) (range of individual means 0.014-0.881 mW/m(2)). Exposure was mainly due to mobile phone base stations (32.0%), mobile phone handsets (29.1%) and digital enhanced cordless telecommunications (DECT) phones (22.7%). Persons owning a DECT phone (total mean 0.15 mW/m(2)) or mobile phone (0.14 mW/m(2)) were exposed more than those not owning a DECT or mobile phone (0.10 mW/m(2)). Mean values were highest in trains (1.16 mW/m(2)), airports (0.74 mW/m(2)) and tramways or buses (0.36 mW/m(2)), and higher during daytime (0.16 mW/m(2)) than nighttime (0.08 mW/m(2)). The Spearman correlation coefficient between mean exposure in the first and second week was 0.61. CONCLUSIONS: Exposure to RF-EMF varied considerably between persons and locations but was fairly consistent within persons. Mobile phone handsets, mobile phone base stations and cordless phones were important sources of exposure in urban Switzerland.

What is Practice Research in Social Work - Definitions, Barriers and Possibilities

Practice is subject to increasing pressure to demonstrate its ability to achieve outcomes required by public policy makers. As part of this process social work practice has to engage with issues around advancing knowledge-based learning processes in a close collaboration with education and research based perspectives. This has given rise to approaches seeking to combine research methodology, field research and practical experience. Practice research is connected to both “the science of the concrete” – a field of research oriented towards subjects more than objects and “mode 2 knowledge production” – an application-oriented research where frameworks and findings are discussed by a number of partners. Practice research is defined into two approaches: practice research – collaboration between practice and research – and practitioner research – processes controlled and accomplished by practitioners. The basic stakeholders in practice research are social workers, service users, administrators, management, organisations, politicians and researchers. Accordingly, practice research is necessarily collaborative, involving a meeting point for different views, interests and needs, where complexity and dilemmas are inherent. Instead of attempting to balance or reconcile these differences, it is important to respect the differences if collaboration is to be established. The strength of both practice and research in practice research is to address these difficult challenges. The danger for both fields is to avoid and reject them.

The Virtual Skeleton Database: An Open Access Repository for Biomedical Research and Collaboration

Background: Statistical shape models are widely used in biomedical research. They are routinely implemented for automatic image segmentation or object identification in medical images. In these fields, however, the acquisition of the large training datasets, required to develop these models, is usually a time-consuming process. Even after this effort, the collections of datasets are often lost or mishandled resulting in replication of work. Objective: To solve these problems, the Virtual Skeleton Database (VSD) is proposed as a centralized storage system where the data necessary to build statistical shape models can be stored and shared. Methods: The VSD provides an online repository system tailored to the needs of the medical research community. The processing of the most common image file types, a statistical shape model framework, and an ontology-based search provide the generic tools to store, exchange, and retrieve digital medical datasets. The hosted data are accessible to the community, and collaborative research catalyzes their productivity. Results: To illustrate the need for an online repository for medical research, three exemplary projects of the VSD are presented: (1) an international collaboration to achieve improvement in cochlear surgery and implant optimization, (2) a population-based analysis of femoral fracture risk between genders, and (3) an online application developed for the evaluation and comparison of the segmentation of brain tumors. Conclusions: The VSD is a novel system for scientific collaboration for the medical image community with a data-centric concept and semantically driven search option for anatomical structures. The repository has been proven to be a useful tool for collaborative model building, as a resource for biomechanical population studies, or to enhance segmentation algorithms.

The COLOSS BEEBOOK Volume I, Standard methods for Apis mellifera research: Introduction

The COLOSS BEEBOOK is a practical manual compiling standard methods in all fields of research on the western honey bee, Apis mellifera. The COLOSS network was founded in 2008 as a consequence of the heavy and frequent losses of managed honey bee colonies experienced in many regions of the world (Neumann and Carreck, 2010). As many of the world’s honey bee research teams began to address the problem, it soon became obvious that a lack of standardized research methods was seriously hindering scientists’ ability to harmonize and compare the data on colony losses obtained internationally. In its second year of activity, during a COLOSS meeting held in Bern, Switzerland, the idea of a manual of standardized honey bee research methods emerged. The manual, to be called the COLOSS BEEBOOK, was inspired by publications with similar purposes for fruit fly research (Lindsley and Grell, 1968; Ashburner 1989; Roberts, 1998; Greenspan, 2004).

The COLOSS BEEBOOK Volume II, Standard methods for Apis mellifera pest and pathogen research: Introduction

The COLOSS BEEBOOK is a practical manual compiling standard methods in all fields of research on the western honey bee, Apis mellifera. The COLOSS network was founded in 2008 as a consequence of the heavy and frequent losses of managed honey bee colonies experienced in many regions of the world (Neumann and Carreck, 2010). As many of the world’s honey bee research teams began to address the problem, it soon became obvious that a lack of standardized research methods was seriously hindering scientists’ ability to harmonize and compare the data on colony losses obtained internationally. In its second year of activity, during a COLOSS meeting held in Bern, Switzerland, the idea of a manual of standardized honey bee research methods emerged. The manual, to be called the COLOSS BEEBOOK, was inspired by publications with similar purposes for fruit fly research (Lindsley and Grell, 1968; Ashburner, 1989; Roberts, 1998; Greenspan, 2004).

How Comprehensible, Interesting and Relevant is Current Research in Traditional Chinese Medicine for Practitioners?

Purpose: In traditional Chinese medicine (TCM) as in other fields of complementary medicine, research does not necessarily follow the sequence from in vitro studies via phase I to phase IV clinical trials, but all steps are being investigated simultaneously. Here, we aimed to investigate which kinds of studies were interesting and relevant for practitioners. Methods: Thirty abstracts from articles on TCM published between April and June 2012 were randomly chosen, including 5 abstracts each of in vitro studies, animal studies, case reports or series, studies with healthy volunteers, trials with patients, or reviews and meta-analyses. Six TCM practitioners (2 female, 5 non-medical, average age 46 years, average practical TCM experience 9 years) rated 10 abstracts each on a 5 point Likert scale (1=very poor to 5=very good) regarding comprehensibility, interest, relevance to practice, information for patients, and promoting reputation of TCM. Average ratings for each group of abstracts were calculated. Results: Comprehensibility of the abstracts was generally rated as good. Case reports/series, studies in healthy volunteers and trials with patients were rated interesting by the practitioners (average rating = 3.7, 3.8 and 3.7, respectively). Relevance to practice was mediocre for all types (2.5 to 3.5). In vitro studies and reviews/meta-analyses were not rated useful as information for patients (2.0). Reviews/Meta-analyses were considered negative for the reputation of TCM (2.2). Conclusions: Practitioners of TCM find abstracts of study results generally comprehensible and interesting. Case reports/series were rated in a similar way as trials with patients. Although TCM is commonly taught by means of case reports, practitioners seemed to value clinical trials. Abstracts of reviews/meta-analyses were rated rather uninformative, which was possibly due to several inconclusive results and the lack of detailed information in these abstracts.