Spanning Tree Objective Functions and Algorithms for Wireless Networks

This paper considers various forms of objective function that may be applied in the calculation of spanning trees in different network situations. Conventional link and path cost approaches are compared to those based on switch or bridge costs more appropriate for wireless applications. Variant objectives are formulated and compared. Although efficient exact algorithmic approaches exist only for the link cost objectives, reasonable approximations for the switch/bridge equivalents are to be found with simple greedy heuristics and better results still through various forms of iterated local search such as tabu search and simulated annealing

Finding Optimal Solutions to Backbone Minimisation Problems using Mixed Integer Programming

Attempts to evaluate heuristic algorithms are often hampered by the lack of known exact solutions with which to compare results. This is true, in particular, in the study of network backbone design - to date, a fairly undeveloped area in mathematical optimisation. This paper uses a Mixed Integer Programming (MIP) approach to find optimal solutions to the problem of backbone minimisation in mesh networks. A simple model is formulated and then adapted to reduce the number of variables and constraints. Network reliability issues are then considered and a more complex model introduced. Finally the model is solved using a commercial solver to generate test instances with which to test the accuracy of a simulated annealing (SA) heuristic. The heuristic is shown to be accurate to within a very small error margin and the strengths and weaknesses of the two approaches are discussed

Optimisation Techniques for Wireless Networks

This paper introduces two new algorithms for the minimum connected dominating set problem. The problem and its relevance to various aspects of wireless network optimisation are briefly outlined followed by a description of the suggested techniques. Results show that these algorithms outperform a number of previous approaches in terms of solution quality and potential for future work is discussed

How do informal self-care strategies evolve among patients with chronic obstructive pulmonary disease managed in primary care? A qualitative study

Background: There is much description in the literature of how patients with chronic obstructive pulmonary disease (COPD) manage their breathlessness and engage in self-care activities; however, little of this is from the perspective of those with less severe disease, who are primarily managed in primary care. This study aimed to understand the self-care experiences of patients with COPD who are primarily managed in primary care, and to examine the challenges of engaging in such behaviors. Methods: Semistructured interviews were carried out with 15 patients with COPD as part of a larger project evaluating a self-management intervention. Thematic analysis was supported by NVivo software (version 8, QSR International, Melbourne, Australia). Results: Three main themes are described, ie, experiencing and understanding symptoms of COPD, current self-care activities, and the importance of family perceptions in managing COPD. Conclusion: Self-care activities evolved spontaneously as participants experienced symptoms of COPD. However, there was a lack of awareness about whether these strategies would impact upon symptoms. Perceptions of COPD by family members posed a challenge to self-care for some participants. Health care professionals should elicit patients' prior disease experiences and utilize spontaneous attempts at disease management in future self-management. These findings have implications for promoting self-management and enhancing quality of life

Power Training Improves the Sensorimotor Cortical Oscillations in Youth with Cerebral Palsy

Background: Our magnetoencephalographic (MEG) brain imaging studies have shown that youth with cerebral palsy (CP) demonstrate altered sensorimotor beta (18-24Hz) cortical oscillations when controlling their leg motor actions and these anomalous cortical oscillations are linked with the extent of their mobility impairments. Current therapeutic trends for improving mobility have shifted from strength training to high-velocity power training, which has shown improvements in isokinetic strength, power production and mobility of youth with CP. However, no studies have assessed whether these clinically relevant improvements are linked with changes in the sensorimotor cortical oscillations. The objective of this study was to utilize MEG brain imaging to examine the potential changes in sensorimotor cortical oscillations following power training. Methods: Youth with CP (N=11; Age=15.9 ±1.1yrs; GMFCS I-III) and neurotypical controls (NT) (N=16; Age=14.6 ±0.8yrs) were recruited to participate in this study. The youth with CP underwent 24 high-velocity leg press power training sessions that were performed on a Total Gym® sled. Pre-Post bilateral leg press 1-repetition maximum (1RM) and peak power production were used to assess the muscular performance changes. The 1-minute walk was used to assess mobility changes. During MEG recordings, participants used their right leg to complete a goal-directed isometric target-matching task. Advanced beamforming methods were subsequently used to image the strength of the sensorimotor beta oscillatory power. The NTs only underwent the baseline MEG assessment. Results: Youth with CP increased their 1RM (Pre=158.3 ±24.7kg, Post=247.5 ±41.5kg, p\u3c0.01), and peak power production (Pre=509.9 ±64.7W, Post=677.1 ±113.3W, p=0.04). Participants with CP also improved their 1-minute walk (Pre=77.4 ±9.2m, Post=80.8 ±8.4m, p = 0.02). The beta sensorimotor cortical oscillations in the leg region were stronger in the youth with CP prior to training compared with the NTs (CP=-25.9±1.8%; NT=-17.2±3.6%, p=0.04). However, the youth with CP had a reduction in the strength of the beta oscillations after undergoing the power training (pre=-25.9 ±1.8%, post=-14.8 ±3.6%, p=0.02), and the strength of the oscillations was not significantly different from the NTs after training (p=0.68). Lastly, the peak power production after training was tightly linked with the strength of the post-therapy sensorimotor cortical oscillations (r=0.79, p=0.03). Conclusion: Power training appears to improve the neural generators that control the leg motor actions, and these neuroplastic changes partly contribute to improvements in the peak power production of youth with CP. Potentially, power training might provide the key therapeutic ingredients for complementary muscular and neurological plastic change.https://digitalcommons.unmc.edu/chri_forum/1001/thumbnail.jp

Ventilatory requirements of quadriceps resistance training in people with COPD and healthy controls.

BACKGROUND: It is proposed that resistance training (RT) does not activate the cardiopulmonary system to the same extent as whole-body exercise. This is important for patients with chronic obstructive pulmonary disease (COPD) who are ventilatory limited. OBJECTIVE: The aim was to assess the ventilatory response to an isokinetic quadriceps RT program in people with COPD and healthy controls. DESIGN: Observational. REGISTRATION NUMBER: ISRCTN22764439. SETTING: Outpatient, university teaching hospital. PARTICIPANTS AND OUTCOME MEASURES: People with COPD (n=14) and healthy controls (n=11) underwent breath-by-breath analysis of their ventilation during an RT session (five sets of 30 maximal knee extensions at 180°/sec). Subjects performed a maximal cycle ergometry test (CET) at baseline. Peak ventilation (VE; L/min) and oxygen consumption (VO2; mL/kg/min) were collected. The same system measured VO2 and VE during the RT session. Parameters are presented as a percentage of the maximal CET. Isokinetic workload, symptom scores, heart rate (HR), and oxygen saturation were documented post-training. RESULTS: People with COPD worked at higher percentages of their maximal capacity than controls (mean range between sets 1-5 for VO2 =49.1%-60.1% [COPD], 45.7%-51.43% [controls] and for VE =57.6%-72.2% [COPD], 49.8%-63.6% [controls]), although this was not statistically significant (P>0.1 in all cases). In absolute terms, the difference between groups was only significant for actual VO2 on set 2 (P<0.05). Controls performed more isokinetic work than patients with COPD (P<0.05). Median Borg symptom scores after RT were the same in both groups (3 breathlessness, 13 exertion), no de-saturation occurred, and both groups were training at ≥65% of their maximum HR. CONCLUSION: No statistically significant differences were found between people with COPD and healthy controls for VO2 and VE achieved during training. The symptoms associated with training were within acceptable limits

A comparison of a structured home-based rehabilitation programme with conventional supervised pulmonary rehabilitation:A randomised non-inferiority trial

Background: Standardised home-based pulmonary rehabilitation (PR) programmes offer an alternative model to centre-based supervised PR for which uptake is currently poor. We determined if a structured home-based unsupervised PR programme was non-inferior to supervised centre-based PR for participants with COPD. Methods: A total of 287 participants with COPD who were referred to PR (187 male, mean (SD) age 68 (8.86) years, FEV1% predicted 48.34 (17.92)) were recruited. They were randomised to either centre-based PR or a structured unsupervised home-based PR programme including a hospital visit with a healthcare professional trained in motivational interviewing, a self-management manual and two telephone calls. Fifty-eight (20%) withdrew from the centre-based group and 51 (18%) from the home group. The primary outcome was dyspnoea domain in the chronic respiratory disease questionnaire (Chronic Respiratory Questionnaire Self-Report; CRQ-SR) at 7 weeks. Measures were taken blinded. We undertook a modified intention-to-treat (mITT) complete case analysis, comparing groups according to original random allocation and with complete data at follow-up. The non-inferiority margin was 0.5 units. Results: There was evidence of significant gains in CRQ-dyspnoea at 7 weeks in both home and centre-based groups. There was inconclusive evidence that home-based PR was non-inferior to PR in dyspnoea (mean group difference, mITT: −0.24, 95% CI −0.61 to 0.12, p=0.18), favouring the centre group at 7 weeks. Conclusions: The standardised home-based programme provides benefits in dyspnoea. Further evidence is needed to definitively determine if the health benefits of the standardised home-based programme are non-inferior or equivalent to supervised centre-based rehabilitation

The development and pilot testing of the Self-management Programme of Activity, Coping and Education for Chronic Obstructive Pulmonary Disease (SPACE for COPD)

Purpose: There is no independent standardized self-management approach available for chronic obstructive pulmonary disease (COPD). The aim of this project was to develop and test a novel self-management manual for individuals with COPD. Patients: Participants with a confirmed diagnosis of COPD were recruited from primary care. Methods: A novel self-management manual was developed with health care professionals and patients. Five focus groups were conducted with individuals with COPD (N = 24) during development to confirm and enhance the content of the prototype manual. The Self-management Programme of Activity, Coping and Education for Chronic Obstructive Pulmonary Disease (SPACE for COPD) manual was developed as the focus of a comprehensive self-management approach facilitated by health care professionals. Preference for delivery was initial face-to-face consultation with telephone follow-up. The SPACE for COPD manual was piloted with 37 participants in primary care. Outcome measures included the Self-Report Chronic Respiratory Questionnaire, Incremental Shuttle Walk Test, and Endurance Shuttle Walking Test (ESWT); measurements were taken at baseline and 6 weeks. Results: The pilot study observed statistically significant improvements for the dyspnea domain of the Self-Report Chronic Respiratory Questionnaire and ESWT. Dyspnea showed a mean change of 0.67 (95% confidence interval 0.23–1.11, P = 0.005). ESWT score increased by 302.25 seconds (95% confidence interval 161.47–443.03, P &lt; 0.001). Conclusion: This article describes the development and delivery of a novel self-management approach for COPD. The program, incorporating the SPACE for COPD manual, appears to provoke important changes in exercise capacity and breathlessness for individuals with COPD managed in primary care

Changes in physical activity during hospital admission for chronic respiratory disease: Inpatient step count does not recover

Background and objectiveEstablishing the amount of inpatient physical activity (PA) undertaken by individuals hospitalized for chronic respiratory disease is needed to inform interventions. This observational study investigated whether PA changes when a person is an inpatient, how long is required to obtain representative PA measures and whether PA varies within a day and between patients of differing lengths of stay.MethodsA total of 389 participants were recruited as early as possible into their hospitalization. Patients wore a PA monitor from recruitment until discharge. Step count was extracted for a range of wear time criteria. Single‐day intraclass correlation coefficients (ICC) were calculated, with an ICC ≥ 0.80 deemed acceptable.ResultsPA data were available for 259 participants. No changes in daily step count were observed during the inpatient stay (586 (95% CI: 427–744) vs 652 (95% CI: 493–812) steps/day for day 2 and 7, respectively). ICC across all wear time criteria were > 0.80. The most stringent wear time criterion, retaining 80% of the sample, was ≥11 h on ≥1 day. More steps were taken during the morning and afternoon than overnight and evening. After controlling for the Medical Research Council (MRC) grade or oxygen use, there was no difference in step count between patients admitted for 2–3 days (short stay) and those admitted for 7–14 days (long stay).ConclusionPatients move little during their hospitalization, and inpatient PA did not increase during their stay. A wear time criterion of 11 waking hours on any single day was representative of the entire admission whilst retaining an acceptable proportion of the initial sample size. Patients may need encouragement to move more during their hospital stay

Lymphangiogenesis and lymph node metastasis in breast cancer

<p>Abstract</p> <p>Introduction</p> <p>There have been few studies on lymphangiogenesis in the past due to the lack of specific lymphatic endothelial markers, and lymphatic-specific growth factors. Recently, these limitations have been relieved by the discovery of a small number of potential lymphatic-specific markers. The relationship between lymphangiogenesis and regional or distant metastasis has not previously been investigated in humans. Using these lymphatic markers, it is possible to explore the relationship between lymphangiogenesis and tumour metastasis. This study indirectly quantified lymphangiogenesis by measuring mRNA expression of all seven lymphatic markers described above in breast cancers and correlated these markers with lymphatic involvement and survival.</p> <p>The cDNA from 153 frozen archived breast samples were analysed with Q-PCR for all seven lymphangiogenic markers. This was correlated with various prognostic factors as well as patient survival.</p> <p>Results</p> <p>There was significantly greater expression of all 7 markers in malignant compared to benign breast tissue. In addition, there was greater expression in lymph node positive/grade 3 tumours when compared to lymph node negative/grade 1 tumours. In 5 of the markers, there was a greater expression in poor NPI prognostic tumours when compared to favourable prognostic tumours which was not statistically significant. There was no association between recurrence risk and lymphangiogenic marker expression.</p> <p>Conclusion</p> <p>In summary, the findings from this study show that lymphangiogenesis, measured by specific lymphatic marker expression, is higher in breast cancers than in normal breast tissue. Secondly, breast cancers which have metastasised to the regional lymphatics show higher expression compared to those which have not, although the individual differences for all five markers were not statistically significant.</p