The step Sidorenko property and non-norming edge-transitive graphs

Sidorenko's Conjecture asserts that every bipartite graph H has the Sidorenko property, i.e., a quasirandom graph minimizes the density of H among all graphs with the same edge density. We study a stronger property, which requires that a quasirandom multipartite graph minimizes the density of H among all graphs with the same edge densities between its parts; this property is called the step Sidorenko property. We show that many bipartite graphs fail to have the step Sidorenko property and use our results to show the existence of a bipartite edge-transitive graph that is not weakly norming; this answers a question of Hatami [Israel J. Math. 175 (2010), 125-150].Comment: Minor correction on page

Large homogeneous submatrices

A matrix is homogeneous if all of its entries are equal. Let $P$ be a $2\times 2$ zero-one matrix that is not homogeneous. We prove that if an $n\times n$ zero-one matrix $A$ does not contain $P$ as a submatrix, then $A$ has an $cn\times cn$ homogeneous submatrix for a suitable constant $c>0$. We further provide an almost complete characterization of the matrices $P$ (missing only finitely many cases) such that forbidding $P$ in $A$ guarantees an $n^{1-o(1)}\times n^{1-o(1)}$ homogeneous submatrix. We apply our results to chordal bipartite graphs, totally balanced matrices, halfplane-arrangements and string graphs.Comment: 20 pages, 1 figure, moved Theorem 1.6 to introduction, added its proof + a new application of Theorem 1.

study protocol for two randomized pragmatic trials

Background Chronic low back pain (LBP) and neck pain (NP) are highly prevalent conditions resulting in high economic costs. Treatment guidelines recommend relaxation techniques, such as progressive muscle relaxation, as adjuvant therapies. Self-care interventions could have the potential to reduce costs in the health care system, but their effectiveness, especially in a usual care setting, is unclear. The aim of these two pragmatic randomized studies is to evaluate whether an additional app-delivered relaxation is more effective in the reduction of chronic LBP or NP than usual care alone. Methods/design Each pragmatic randomized two-armed study aims to include a total of 220 patients aged 18 to 65 years with chronic (>12 weeks) LBP or NP and an average pain intensity of ≥ 4 on a numeric rating scale (NRS) in the 7 days before recruitment. The participants will be randomized into an intervention and a usual care group. The intervention group will be instructed to practice one of these 3 relaxation techniques on at least 5 days/week for 15 minutes/day over a period of 6 months starting on the day of randomization: autogenic training, mindfulness meditation, or guided imagery. Instructions and exercises will be provided using a smartphone app, baseline information will be collected using paper and pencil. Follow-up information (daily, weekly, and after 3 and 6 months) will be collected using electronic diaries and questionnaires included in the app. The primary outcome measure will be the mean LBP or NP intensity during the first 3 months of intervention based on daily pain intensity measurements on a NRS (0 = no pain, 10 = worst possible pain). The secondary outcome parameters will include the mean pain intensity during the first 6 months after randomization based on daily measurements, the mean pain intensity measured weekly as the average pain intensity of the previous 7 days over 3 and 6 months, pain acceptance, ‘LBP- and NP-related’ stress, sick leave days, pain medication intake, adherence, suspected adverse reaction, and serious adverse events. Discussion The designed studies reflect a usual self- care setting and will provide evidence on a pragmatic self-care intervention that is easy to combine with care provided by medical professionals

The step Sidorenko property and non-norming edge-transitive graphs

Sidorenko's Conjecture asserts that every bipartite graph H has the Sidorenko property, i.e., a quasirandom graph minimizes the density of H among all graphs with the same edge density. We study a stronger property, which requires that a quasirandom multipartite graph minimizes the density of H among all graphs with the same edge densities between its parts; this property is called the step Sidorenko property. We show that many bipartite graphs fail to have the step Sidorenko property and use our results to show the existence of a bipartite edge-transitive graph that is not weakly norming; this answers a question of Hatami [Israel J. Math. 175 (2010), 125-150]

Five Lessons Learned From Randomized Controlled Trials on Mobile Health Interventions: Consensus Procedure on Practical Recommendations for Sustainable Research

Background: Clinical research on mobile health (mHealth) interventions is too slow in comparison to the rapid speed of technological advances, thereby impeding sustainable research and evidence-based implementation of mHealth interventions. Objective: We aimed to establish practical lessons from the experience of our working group, which might accelerate the development of future mHealth interventions and their evaluation by randomized controlled trials (RCTs). Methods: This paper is based on group and expert discussions, and focuses on the researchers’ perspectives after four RCTson mHealth interventions for chronic pain. Results: The following five lessons are presented, which are based on practical application, increase of speed, and sustainability: (1) explore stakeholder opinions, (2) develop the mHealth app and trial simultaneously, (3) minimize complexity, (4) manage necessary resources, and (5) apply behavior change techniques. Conclusions: The five lessons developed may lead toward an agile research environment. Agility might be the key factor in the development and research process of a potentially sustainable and evidence-based mHealth intervention

Content Representation of Tactile Mental Imagery in Primary Somatosensory Cortex

The imagination of tactile stimulation has been shown to activate primary somatosensory cortex (S1) with a somatotopic specificity akin to that seen during the perception of tactile stimuli. Using fMRI and multivariate pattern analysis, we investigate whether this recruitment of sensory regions also reflects content-specific activation (i.e., whether the activation in S1 is specific to the mental content participants imagined). To this end, healthy volunteers (n = 21) either perceived or imagined three types of vibrotactile stimuli (mental content) while fMRI data were acquired. Independent of the content, during tactile mental imagery we found activation of frontoparietal regions, supplemented with activation in the contralateral BA2 subregion of S1, replicating previous reports. While the imagery of the three different stimuli did not reveal univariate activation differences, using multivariate pattern classification, we were able to decode the imagined stimulus type from BA2. Moreover, cross-classification revealed that tactile imagery elicits activation patterns similar to those evoked by the perception of the respective stimuli. These findings promote the idea that mental tactile imagery involves the recruitment of content-specific activation patterns in sensory cortices, namely in S1

Content Representation of Tactile Mental Imagery in Primary Somatosensory Cortex

The imagination of tactile stimulation has been shown to activate primary somatosensory cortex (S1) with a somatotopic specificity akin to that seen during the perception of tactile stimuli. Using fMRI and multivariate pattern analysis, we investigate whether this recruitment of sensory regions also reflects content-specific activation (i.e., whether the activation in S1 is specific to the mental content participants imagined). To this end, healthy volunteers (n = 21) either perceived or imagined three types of vibrotactile stimuli (mental content) while fMRI data were acquired. Independent of the content, during tactile mental imagery we found activation of frontoparietal regions, supplemented with activation in the contralateral BA2 subregion of S1, replicating previous reports. While the imagery of the three different stimuli did not reveal univariate activation differences, using multivariate pattern classification, we were able to decode the imagined stimulus type from BA2. Moreover, cross-classification revealed that tactile imagery elicits activation patterns similar to those evoked by the perception of the respective stimuli. These findings promote the idea that mental tactile imagery involves the recruitment of content-specific activation patterns in sensory cortices, namely in S1

Effects of blended learning training for oncology physicians to advise their patients about complementary and integrative therapies: results from the multicenter cluster-randomized KOKON-KTO trial

Background: Many oncology physicians are confronted with the topic of complementary and integrative medicine (CIM) by cancer patients. This study examined whether a blended learning (e-learning and a workshop) to train oncology physicians in providing advice on CIM therapies to their cancer patients, in addition to distributing an information leaflet about reputable CIM websites, had different effects on physician-reported outcomes in regard to consultations compared with only distributing the leaflet. Methods: In a multicenter, cluster-randomized trial, 48 oncology physicians were randomly allocated to an intervention group (CIM consultation and an information leaflet) or a control group (information leaflet only). After the training, the oncology physicians conducted 297 consultations with their cancer patients. Measurements were assessed at oncology physician, physician-patient-interaction (measured by external reviewers), and patient levels. This analysis focused on the physician outcomes of stress reaction and perceived consultation skill competency. In addition, qualitative interviews were conducted with a subsample of oncology physicians who experienced both, the intervention and control condition. Results: The oncology physicians in the intervention group showed a lower stress reaction in all measured dimensions after CIM consultations than those in the control group. There was no significant difference between oncology physicians in the intervention and control groups regarding the perceived consultation skill competency (overburden: intervention 1.4 [95% CI: 0.7;2.1]; control 2.1 [95% CI: 1.4;2.7], tension: 1.3 [95% CI: 0.7;2.0] vs. 1.9 [95% CI: 1.3;2.5], and discomfort with consultation situations: 1.0 [95% CI: 0.4;1.7]; vs. 1.7 [95% CI: 1.2;2.3]). The qualitative data showed that only providing the leaflet seemed impersonal to oncology physicians, while the training made them feel well prepared to conduct a full conversation about CIM and provide the information leaflet. Conclusions: In our exploratory study providing structured CIM consultations showed positive effects on the perceived stress of oncology physicians, and the training was subjectively experienced as an approach that improved physician preparation for advising cancer patients about CIM, however no effects regarding perceived consultation skill competency were found

Efficacy of Injections with Disci/Rhus Toxicodendron Compositum for Chronic Low Back Pain – A Randomized Placebo-Controlled Trial

The effectiveness of injection therapy for low-back pain is still debatable. We compared the efficacy of local injections of the homeopathic preparation Disci/Rhus toxicodendron compositum (verum) with placebo injections and with no treatment in patients with chronic low back pain.In a randomized controlled partly double blind multicenter trial patients with chronic low back pain from 9 German outpatient clinics were enrolled and randomly allocated in a 1∶1∶1 ratio to receive subcutaneous injections (verum or placebo) into painful sites on the lower back over 12 treatment sessions within eight weeks, or no treatment (rescue pain medication with paracetamol or NSAIDs). All trial personnel and participants were masked to treatment allocation. The primary outcome measure was the average pain intensity over the last seven days on a visual analogue scale (0-100 mm, 0 = no pain, 100 = worst imaginable pain) after eight weeks. Follow-up was 26 weeks. Primary analysis was by intention to treat. Between August 2007 and June 2008, 150 patients were randomly allocated to three groups (51 verum, 48 placebo and 51 no treatment). The mean baseline-adjusted low back pain intensity at week eight was: verum group 37.0 mm (97.5% CI 25.3;48.8), no treatment group 53.0 (41.8;64.2), and placebo group 41.8 (30.1;53.6). The verum was significantly superior to no treatment (P = 0.001), but not to placebo (P = 0.350). No significant side effects were reported.The homeopathic preparation was not superior to placebo. Compared to no treatment injections resulted in significant and clinical relevant chronic back pain relief.ClinicalTrials.gov NCT00567736

Effects of training oncology physicians advising patients on complementary and integrative therapies on patient‐reported outcomes: A multicenter, cluster‐randomized trial

Background: Many patients with cancer do not disclose complementary medicine use but want their physician's advice on this matter. This study evaluated whether using blended learning (e-learning plus a workshop) to train oncology physicians in providing advice on complementary and integrative medicine (CIM) therapies to their patients with cancer, in addition to distributing an information leaflet on reputable CIM websites, had different effects on patient-reported outcomes for the consultation than only distributing the leaflet. Methods: In this multicenter, cluster-randomized trial, patients from private practices/hospital departments, recruited by 48 oncology physicians randomly allocated to an intervention group (CIM consultation plus information leaflet) or a control group (information leaflet), received CIM information. Patient-reported outcomes included satisfaction (Patient Satisfaction With Information on Cancer Treatment), readiness to make a decision (Preparation for Decision Making), and physician-patient communication (European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire and Communication 26 [EORTC QLQ-COMU26]) for the consultation. Qualitative interviews were conducted with a physician subsample. Results: A total of 291 patients (128 in the intervention group and 169 in the control group) advised by 41 physicians participated. Patients in the intervention group rated physician-patient communication higher on all EORTC QLQ-COMU26 scales (mean total score, 84.3 [95% CI, 79.5-89.2] vs 73.6 [95% CI, 69.3-78.0]; P = .002), were more satisfied with the advice (mean, 4.2 [95% CI, 4.0-4.4] vs 3.7 [95% CI, 3.5-3.8]; P < .001), and were readier to make a decision (mean, 63.5 [95% CI, 57.4-69.6] vs 53.2 [95% CI, 47.8-58.7]; P = .016) than the control group. Physicians who reported patients in both settings seemed satisfied with the advice given. Conclusions: This study evaluated a novel education intervention for training oncology physicians in providing CIM advice in routine care. Providing structured CIM consultations had positive effects on patient satisfaction, readiness to make decisions, and physician-patient communication