Mechanisms for the effect of electric and magnetic fields on biological systems Semiannual status report, Jan. 1969 - Jun. 1969

Electric field effects on dielectric properties and molecular arrangements of cholesteric liquid crystal

Mechanisms for the effect of electric and magnetic fields on biological systems Semiannual status report, Jun. - Dec. 1969

Electric and magnetic field effects on structure and properties of cholesteric liquid crystal

Diagnostic accuracy and added value of dual-energy subtraction radiography compared to standard conventional radiography using computed tomography as standard of reference

PURPOSE: To retrospectively evaluate diagnostic performance of dual-energy subtraction radiography (DESR) for interpretation of chest radiographs compared to conventional radiography (CR) using computed tomography (CT) as standard of reference. MATERIAL AND METHODS: A total of 199 patients (75 female, median age 67) were included in this institutional review board (IRB)-approved clinical trial. All patients were scanned in posteroanterior and lateral direction with dual-shot DE-technique. Chest CT was performed within ±72 hours. The system provides three types of images: bone weighted-image, soft tissue weighted-image, herein termed as DESR-images, and a standard image, termed CR-image (marked as CR-image). Images were evaluated by two radiologists for presence of inserted life support lines, pneumothorax, pleural effusion, infectious consolidation, interstitial lung changes, tumor, skeletal alterations, soft tissue alterations, aortic or tracheal calcification and pleural thickening. Inter-observer agreement between readers and diagnostic performance were calculated. McNemar's test was used to test for significant differences. RESULTS: Mean inter-observer agreement throughout the investigated parameters was higher in DESR images compared to CR-images (kDESR = 0.935 vs. kCR = 0.858). DESR images provided significantly increased sensitivity compared to CR-images for the detection of infectious consolidations (42% vs. 62%), tumor (46% vs. 57%), interstitial lung changes (69% vs. 87%) and aortic or tracheal calcification (25 vs. 73%) (p0.05). CONCLUSION: DESR increases significantly the sensibility without affecting the specificity evaluating chest radiographs, with emphasis on the detection of interstitial lung diseases

Gravitational resonance spectroscopy with an oscillating magnetic field gradient in the GRANIT flow through arrangement

Gravitational resonance spectroscopy consists in measuring the energy spectrum of bouncing ultracold neutrons above a mirror by inducing resonant transitions between different discrete quantum levels. We discuss how to induce the resonances with a flow through arrangement in the GRANIT spectrometer, excited by an oscillating magnetic field gradient. The spectroscopy could be realized in two distinct modes (so called DC and AC) using the same device to produce the magnetic excitation. We present calculations demonstrating the feasibility of the newly proposed AC mode

Modelling the Pioneer anomaly as modified inertia

This paper proposes an explanation for the Pioneer anomaly: an unexplained Sunward acceleration of 8.74 +/- 1.33 x 10^-10 m s^-2 seen in the behaviour of the Pioneer probes. Two hypotheses are made: (1) Inertia is a reaction to Unruh radiation and (2) this reaction is weaker for low accelerations because some wavelengths in the Unruh spectrum do not fit within a limiting scale (twice the Hubble distance) and are disallowed: a process similar to the Casimir effect. When these ideas are used to model the Pioneer crafts' trajectories there is a slight reduction in their inertial mass, causing an anomalous Sunward acceleration of 6.9 +/- 3.5 x 10^-10 m s^-2 which agrees within error bars with the observed Pioneer anomaly beyond 10 AU from the Sun. This new scheme is appealingly simple and does not require adjustable parameters. However, it also predicts an anomaly within 10 AU of the Sun, which has not been observed. Various observational tests for the idea are proposed.Comment: 15 pages, 2 bw figures, accepted by MNRAS 19th December 200

Resilience trinity: safeguarding ecosystem functioning and services across three different time horizons and decision contexts

Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi‐faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time‐horizons: 1) reactive, when there is an imminent threat to ES resilience and a high pressure to act, 2) adjustive, when the threat is known in general but there is still time to adapt management and 3) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology and engineering are often implicitly focussing on provident, adjustive or reactive resilience, respectively, but these different notions of resilience and their corresponding social, ecological and economic tradeoffs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer‐term management actions are not missed while urgent threats to ES are given priority

Surgery for women with apical vaginal prolapse (Review)

Background: Apical vaginal prolapse is a descent of the uterus or vaginal vault (post-hysterectomy). Various surgical treatments are available and there are no guidelines to recommend which is the best. Objectives: To evaluate the safety and efficacy of any surgical intervention compared to another intervention for the management of apical vaginal prolapse. Search methods: We searched the Cochrane Incontinence Group's Specialised Register of controlled trials, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, ClinicalTrials.gov, WHO ICTRP and handsearching of journals and conference proceedings (searched July 2015) and ClinicalTrials.gov (searched January 2016). Selection criteria: We included randomised controlled trials (RCTs). Data collection and analysis: We used Cochrane methods. Our primary outcomes were awareness of prolapse, repeat surgery and recurrent prolapse (any site). Main results: We included 30 RCTs (3414 women) comparing surgical procedures for apical vaginal prolapse. Evidence quality ranged from low to moderate. Limitations included imprecision, poor methodological reporting and inconsistency. Vaginal procedures versus sacral colpopexy (six RCTs, n = 583; one to four-year review). Awareness of prolapse was more common after vaginal procedures (risk ratio (RR) 2.11, 95% confidence interval (CI) 1.06 to 4.21, 3 RCTs, n = 277, I = 0%, moderate-quality evidence). If 7% of women are aware of prolapse after sacral colpopexy, 14% (7% to 27%) are likely to be aware after vaginal procedures. Repeat surgery for prolapse was more common after vaginal procedures (RR 2.28, 95% CI 1.20 to 4.32; 4 RCTs, n = 383, I = 0%, moderate-quality evidence). The confidence interval suggests that if 4% of women require repeat prolapse surgery after sacral colpopexy, between 5% and 18% would require it after vaginal procedures. We found no conclusive evidence that vaginal procedures increaserepeat surgery for stress urinary incontinence (SUI) (RR 1.87, 95% CI 0.72 to 4.86; 4 RCTs, n = 395; I = 0%, moderate-quality evidence). If 3% of women require repeat surgery for SUI after sacral colpopexy, between 2% and 16% are likely to do so after vaginal procedures. Recurrent prolapse is probably more common after vaginal procedures (RR 1.89, 95% CI 1.33 to 2.70; 4 RCTs, n = 390; I = 41%, moderate-quality evidence). If 23% of women have recurrent prolapse after sacral colpopexy, about 41% (31% to 63%) are likely to do so after vaginal procedures. The effect of vaginal procedures on bladder injury was uncertain (RR 0.57, 95% CI 0.14 to 2.36; 5 RCTs, n = 511; I = 0%, moderate-quality evidence). SUI was more common after vaginal procedures (RR 1.86, 95% CI 1.17 to 2.94; 3 RCTs, n = 263; I = 0%, moderate-quality evidence). Dyspareunia was also more common after vaginal procedures (RR 2.53, 95% CI 1.17 to 5.50; 3 RCTs, n = 106, I = 43%, low-quality evidence). Vaginal surgery with mesh versus without mesh (6 RCTs, n = 598, 1-3 year review). Awareness of prolapse - There may be little or no difference between the groups for this outcome (RR 1.08 95% CI 0.35 to 3.30 1 RCT n = 54, low quality evidence). The confidence interval was wide suggesting that if 18% of women are aware of prolapse after surgery without mesh, between 6% and 59% will be aware of prolapse after surgery with mesh. Repeat surgery for prolapse - There may be little or no difference between the groups for this outcome (RR 0.69, 95% CI 0.30 to 1.60; 5 RCTs, n = 497; I = 9%, low-quality evidence). If 4% of women require repeat surgery for prolapse after surgery without mesh, 1% to 7% are likely to do so after surgery with mesh. We found no conclusive evidence that surgery with mesh increases repeat surgery for SUI (RR 4.91, 95% CI 0.86 to 27.94; 2 RCTs, n = 220; I = 0%, low-quality evidence). The confidence interval was wide suggesting that if 2% of women require repeat surgery for SUI after vaginal colpopexy without mesh, 2% to 53% are likely to do so after surgery with mesh. We found no clear evidence that surgery with mesh decreases recurrent prolapse (RR 0.36, 95% CI 0.09 to 1.40; 3 RCTs n = 269; I = 91%, low-quality evidence). The confidence interval was very wide and there was serious inconsistency between the studies. Other outcomesThere is probably little or no difference between the groups in rates of SUI (de novo) (RR 1.37, 95% CI 0.94 to 1.99; 4 RCTs, n = 295; I = 0%, moderate-quality evidence) or dyspareunia (RR 1.21, 95% CI 0.55 to 2.66; 5 RCTs, n = 501; I = 0% moderate-quality evidence). We are uncertain whether there is any difference for bladder injury (RR 3.00, 95% CI 0.91 to 9.89; 4 RCTs, n = 445; I = 0%; very low-quality evidence). Vaginal hysterectomy versus alternatives for uterine prolapse (six studies, n = 667) No clear conclusions could be reached from the available evidence, though one RCT found that awareness of prolapse was less likely after hysterectomy than after abdominal sacrohysteropexy (RR 0.38, 955 CI 0.15 to 0.98, n = 84, moderate-quality evidence). Other comparisons There was no evidence of a difference for any of our primary review outcomes between different types of vaginal native tissue repair (two RCTs), comparisons of graft materials for vaginal support (two RCTs), different routes for sacral colpopexy (four RCTs), or between sacral colpopexy with and without continence surgery (four RCTs). Authors' conclusions: Sacral colpopexy is associated with lower risk of awareness of prolapse, recurrent prolapse on examination, repeat surgery for prolapse, postoperative SUI and dyspareunia than a variety of vaginal interventions. The limited evidence does not support use of transvaginal mesh compared to native tissue repair for apical vaginal prolapse. Most of the evaluated transvaginal meshes are no longer available and new lighter meshes currently lack evidence of safety The evidence was inconclusive when comparing access routes for sacral colpopexy. No clear conclusion can be reached from the available data comparing uterine preserving surgery versus vaginal hysterectomy for uterine prolapse

Diagnostic accuracy and added value of dual-energy subtraction radiography compared to standard conventional radiography using computed tomography as standard of reference

PURPOSE: To retrospectively evaluate diagnostic performance of dual-energy subtraction radiography (DESR) for interpretation of chest radiographs compared to conventional radiography (CR) using computed tomography (CT) as standard of reference. MATERIAL AND METHODS: A total of 199 patients (75 female, median age 67) were included in this institutional review board (IRB)-approved clinical trial. All patients were scanned in posteroanterior and lateral direction with dual-shot DE-technique. Chest CT was performed within ±72 hours. The system provides three types of images: bone weighted-image, soft tissue weighted-image, herein termed as DESR-images, and a standard image, termed CR-image (marked as CR-image). Images were evaluated by two radiologists for presence of inserted life support lines, pneumothorax, pleural effusion, infectious consolidation, interstitial lung changes, tumor, skeletal alterations, soft tissue alterations, aortic or tracheal calcification and pleural thickening. Inter-observer agreement between readers and diagnostic performance were calculated. McNemar's test was used to test for significant differences. RESULTS: Mean inter-observer agreement throughout the investigated parameters was higher in DESR images compared to CR-images (kDESR = 0.935 vs. kCR = 0.858). DESR images provided significantly increased sensitivity compared to CR-images for the detection of infectious consolidations (42% vs. 62%), tumor (46% vs. 57%), interstitial lung changes (69% vs. 87%) and aortic or tracheal calcification (25 vs. 73%) (p<0.05). There were no significant differences in sensitivity for the detection of inserted life support lines, pneumothorax, pleural effusion, skeletal alterations, soft tissue alterations or pleural thickening (p>0.05). CONCLUSION: DESR increases significantly the sensibility without affecting the specificity evaluating chest radiographs, with emphasis on the detection of interstitial lung diseases

Transitions between levels of a quantum bouncer induced by a noise-like perturbation

The probability of transition between levels of a quantum bouncer, induced by a noise-like perturbation, is calculated. The results are applied to two sources of noise (vibrations and mirror surface waviness) which might play an important role in future GRANIT experiment, aiming at precision studies of/with the neutron quantum bouncer