Crossover behavior for complex order parameter in high-Tc superconductors

A number of recent experiments have suggested the presence of either real or complex components in the gap symmetry of high-$T_c$ superconductors (HTSC). In this paper we introduce a novel approach to study the competition of such complex order parameter mixtures by varying the position of the two-body attractive potential in a two dimensional extended Hubbard Hamiltonian. We show that this procedure explain a number of experimental results and on the theoretical side, it may be related with certain HTSC microscopic models like the spin fluctuation theory. Following current trends we concentrate on the study of $d_{x^2-y^2}$ order parameter with a component of the type $d_{xy}$ or a s-wave like $s_{x^2+y^2}$ and $s_{xy}$ symmetry. We show that the position of the optimal s-component peak changes with the position parameter $b$ while the d-component occurs always in the optimally region around hole content $\rho \approx 0.39$.Comment: 6 pages in RevTex, 5 figs. in epsi, accepted in the Physica

Change processes underlying 'good outcome' : a qualitative study on recovered and improved patients’ experiences in psychotherapy for major depression

Aim: Exploring change processes underlying "good outcome" in psychotherapy for major depression. We examined the perspectives of patients who "recovered" and "improved" (Jacobson & Truax) following time-limited CBT and PDT. Method: In the context of an RCT on the treatment of major depression, patients were selected based on their pre-post outcome scores on the BDI-II: we selected 28 patients who recovered and 19 who improved in terms of depressive symptoms. A grounded theory analysis was conducted on post-therapy client change interviews, resulting in an integrative conceptual model. Results: According to recovered and improved patients, change follows from an interaction between therapy, therapist, patient, and extra-therapeutic context. Both helping and hindering influences were mentioned within all four influencing factors. Differences between recovered and improved patients point at the role of patients' agency and patients' internal and external obstacles. However, patients marked as "improved" described heterogeneous experiences. CBT- and PDT-specific experiences were also observed, although our findings suggest the possible role of therapist-related influences. Conclusion: From patients' perspectives, various change processes underlie "good outcome" that do not necessarily imply an "all good process". This supports a holistic, multidimensional conceptualization of change processes in psychotherapy and calls for more fine-grained mixed-methods process-outcome research

Applications of integer programming methods to cages

The aim of this paper is to construct new small regular graphs with girth 7 using integer programming techniques. Over the last two decades solvers for integer programs have become more and more powerful and have proven to be a useful aid for many hard combinatorial problems. Despite successes in many related fields, these optimisation tools have so far been absent in the quest for small regular graphs with a given girth. Here we illustrate the power of these solvers as an aid to construct small regular girth 7 graphs from girth 8 cage

Does military combat-related traumatic injury increase cardiovascular disease risk?

Background: Cutting edge battlefield trauma care has allowed military personnel to survive complex injuries that historically would not have been possible. There is largely historical evidence suggesting that combat related traumatic injury (CRTI) is associated with an increased cardiovascular (CV) disease (CVD) risk. However, data from a contemporary military population with CRTI is lacking. Hypotheses: The main hypotheses addressed in this thesis are: 1. Military servicemen who have had suffered severe CRTI with limb amputations have increased arterial stiffness compared to those less severely injured and non-injured servicemen. 2. Combat-related traumatic amputation is associated with greater vascular inflammation and a more adverse lipid profile than that observed with less severe combat related injuries and with non-injured servicemen exposed to the same operational environment. Methods: This was a cross-sectional observational study that included the first 699 male British military personnel who took part in the ongoing ADVANCE (ArmeD SerVices TrAuma RehabilitatioN OutComE) study project. CRTI veterans with limb amputations (CRTI-A, n=105) and CRTI veterans without limb amputations (CRTI-NA, n=200) were compared with a frequency-matched healthy control population (n=394) of servicemen of similar age and operational exposure (Afghanistan 2003-14). Fasting serum lipids, glucose and Hs-CRP levels were measured using venous blood. Arterial stiffness (expressed as central [AIx] and peripheral [pAI] Augmentation Index), pulse wave velocity (PWV), brachial and central aortic blood pressure, subendocardial viability ratio (SEVR), an indirect marker of myocardial blood perfusion, were measured using the Vicorder device. Injury severity was determined using the New Injury Severity Score (NISS) and the association of injury severity score and CVD risk profile was assessed. Results: The mean age was 33.9 (± 5.40) [range 23-60] years with the time from injury or deployment to examination averaging 90.4 (± 20.99) months. The NISS were higher in the CRTI-A vs CRT-NA vs control 36.75 (± 18.01) vs 20.11 (± 17.9) vs 0; p<0.001 respectively. Resting heart rate (minute-1) was significantly higher amongst those with CRTI-A, 63.67 ( ± 12.53) vs CRTI-NA group 58.35 (± 9.41) and, healthy controls 56.39 (± 9.24); p<0.001, with no significant difference in respective HDL Cholesterol levels 1.120 (± 0.27) vs 1.249 (± 0.33) vs 1.252 (± 0.27) mmol/l; p<0.001. PWV, AIx or central blood pressure. The SEVR values, 194.0 (± 43.32) vs 201.3 (± 45.07) vs 208.5 (± 63.04); p=0.0101) respectively, were significantly lower whereas Hs-CRP, 2.60 (± 3.81)mg/l vs 1.96 (± 2.68)mg/l vs 1.44 (± 1.69)mg/l; p=0.0166 respectively and total cholesterol/HDL ratio 4.49 (±1.25) vs 4.31 (±1.82) vs 4.19 (±1.48); p=0.012, respectively, were significantly greater among the CRTI-A compared with the CRTI-NA and healthy controls. These differences were most marked with proximal bilateral amputations. Conclusion: Servicemen who have sustained severe CRTI-A have a worse CVD risk profile with evidence of greater vascular inflammation and a more adverse lipid profile than those without amputations or injury. However, there was no significant difference in arterial stiffness. These findings confirm the need for a long-term cohort study to assess whether these differences in risk profile will translate into meaningful variance in CVD outcomes

Centrifugal Compressor Degradation Detection Through Remote Vibration Monitoring.

Case StudyAn example of availability gain using vibration remote monitoring systems for early diagnostic