Local master equations bypass the secular approximation

This is the author accepted manuscript. The final version is available on open access from Verein zur Förderung des Open Access Publizierens in den Quantenwissenschaften via the DOI in this recordMaster equations are a vital tool to model heat flow through nanoscale thermodynamic systems. Most practical devices are made up of interacting sub-system, and are often modelled using either local master equations (LMEs) or global master equations (GMEs). While the limiting cases in which either the LME or the GME breaks down are well understood, there exists a 'grey area' in which both equations capture steady-state heat currents reliably, but predict very different transient heat flows. In such cases, which one should we trust? Here, we show that, when it comes to dynamics, the local approach can be more reliable than the global one for weakly interacting open quantum systems. This is due to the fact that the secular approximation, which underpins the GME, can destroy key dynamical features. To illustrate this, we consider a minimal transport setup and show that its LME displays exceptional points (EPs). These singularities have been observed in a superconducting-circuit realisation of the model [1]. However, in stark contrast to experimental evidence, no EPs appear within the global approach. We then show that the EPs are a feature built into the Redfield equation, which is more accurate than the LME and the GME. Finally, we show that the local approach emerges as the weak-interaction limit of the Redfield equation, and that it entirely avoids the secular approximation.Engineering and Physical Sciences Research Council (EPSRC)Royal Societ

Mirrored images but not silicone models trigger aggressive responses in male common wall lizards

Disentangling the effects of single releasers in animal communication is a demanding task because a releaser often consists of a combination of different key stimuli. Territorial communication in reptiles usually depends on visual, chemical, and acoustic stimuli, but the role of each of them depends on phylogeny. Lacertids are modern lizards that rely mainly on chemical cues for their communication, but they also use aggressive displays based on visual recognition. We experimentally tested the visual stimuli that release an aggressive response in the males of a typical lacertid, the common wall lizard (Podarcis muralis), testing the effects of silicone models and mirrored images in captivity. The response to models and control (a blank sheet) was not significantly different and these stimuli did not release any aggressive behaviour. On the contrary, the reflected image in a mirror caused overt aggression (i.e., bites against it) in 63% of tested individuals. The results clearly demonstrate the role of visual stimuli in territorial communication, but only as a combined effect of shape and motion, differently from other lizard families for which shape is enough to stimulate aggre sive responses. Mirrors can be useful tools to investigate aggression related to physiological and morphological aspects in lacertid lizards

Fate of patients with spinal cord ischemia complicating thoracic endovascular aortic repair

ObjectiveSpinal cord ischemia (SCI) is a potentially devastating complication of thoracic endovascular aortic repair (TEVAR) that can result in varying degrees of short-term and permanent disability. This study was undertaken to describe the clinical outcomes, long-term functional impact, and influence on survival of SCI after TEVAR.MethodsA retrospective review of all TEVAR patients at the University of Florida from 2000 to 2011 was performed to identify individuals experiencing SCI, defined by any new lower extremity neurologic deficit not attributable to another cause. SCI was dichotomized into immediate or delayed onset, with immediate onset defined as SCI noted upon awakening from anesthesia, and delayed characterized as a period of normal function, followed by development of neurologic injury. Ambulatory status was determined using database query, record review, and phone interviews with patients and/or family. Mortality was estimated using life-table analysis.ResultsA total of 607 TEVARs were performed for various indications, with 57 patients (9.4%) noted to have postoperative SCI (4.3% permanent). SCI patients were more likely to be older (63.9 ± 15.6 vs 70.5 ± 11.2 years; P = .002) and have a number of comorbidities, including chronic obstructive pulmonary disease, hypertension, dyslipidemia, and cerebrovascular disease (P < .0001). At some point in their care, a cerebrospinal fluid drain was placed in 54 patients (95%), with 54% placed postoperatively. In-hospital mortality was 8.8% for the entire cohort (SCI vs no SCI; P = .45). SCI developed immediately in 12 patients, delayed onset in 40, and indeterminate in five patients due to indiscriminate timing from postoperative sedation. Three patients (25%) with immediate SCI had measurable functional improvement (FI), whereas 28 (70%) of the delayed-onset patients experienced some degree of neurologic recovery (P = .04). Of the 34 patients with complete data available, 26 (76%) reported quantifiable FI, but only 13 (38%) experienced return to their preoperative baseline. Estimated mean (± standard error) survival for patients with and without SCI was 37.2 ± 4.5 and 71.6 ± 3.9 months (P < .0006), respectively. Patients with FI had a mean survival of 53.9 ± 5.9 months compared with 9.6 ± 3.6 months for those without improvement (P < .0001). Survival and return of neurologic function were not significantly different when patients with preoperative and postoperative cerebrospinal fluid drains were compared.ConclusionsThe minority of patients experience complete return to baseline function after SCI with TEVAR, and outcomes in patients without early functional recovery are particularly dismal. Patients experiencing delayed SCI are more likely to have FI and may anticipate similar life-expectancy with neurologic recovery compared with patients without SCI. Timing of drain placement does not appear to have an impact on postdischarge FI or long-term mortality

Prediction of graft patency and mortality after distal revascularization and interval ligation for hemodialysis access-related hand ischemia

ObjectiveThe treatment goals of access-related hand ischemia (ARHI) are to reverse symptoms and salvage the access. Many procedures have been described, but the optimal treatment strategy remains unresolved. In an effort to guide clinical decision making, this study was undertaken to document our outcomes for distal revascularization and interval ligation (DRIL) and to identify predictors of bypass patency and patient mortality.MethodsA retrospective review was performed of all patients who underwent DRIL at the University of Florida from 2002 to 2011. Diagnosis of ARHI was based primarily upon clinical symptoms with noninvasive studies used to corroborate in equivocal cases. Patient demographics, procedure-outcome variables, and reinterventions were recorded. Bypass patency and mortality were estimated using cumulative incidence and Kaplan-Meier methodology, respectively. Cumulative incidence and Cox regression analysis were performed to determine predictors of bypass patency and mortality, respectively.ResultsA total of 134 DRILs were performed in 126 patients (mean [standard deviation] age, 57 [12] years) following brachial artery-based access. The postoperative complication rate was 27% (19% wound), and 30-day mortality was 2%. The wrist-brachial index and digital brachial index increased 0.31 (0.25) and 0.25 (0.29), respectively. Symptoms resolved in 82% of patients, and 85% continued to use their access. Cumulative incidences (± standard error of the mean) of loss of primary and primary-assisted patency rates were 5% ± 2% and 4% ± 2% at 1 year and 22% ± 5% and 18% ± 5% at 5 years, respectively, with mean follow-up of 14.8 months. Univariate predictors of primary patency failure were DRIL complications (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.2-8.9; P = .02), configuration other than brachiobasilic/brachiocephalic autogenous access (OR, 3.4; 95% CI, 1.4-8.3; P = .009), and two or more prior access attempts (OR, 4.1; 95% CI, 1.6-10.4; P = .004). Brachiocephalic access configuration (OR, 0.2; 95% CI, 0.04-0.8; P = .02) and autogenous vein conduit (OR, 0.2; 95% CI, 0.06-0.58; P = .004) were predictors of improved bypass patency. All-cause mortality was 28% and 79% at 1 and 5 years, respectively. Multivariable predictors of mortality were age >40 (hazard ratio [HR], 8.3; 95% CI, 2.5-33.3; P = .0004), grade 3 ischemia (HR, 2.6; 95% CI, 1.5-4.6; P = .0008), complication from DRIL (HR, 2.4; 95% CI, 1.3-4.5; P = .004), and smoking history (HR, 2.2; 95% CI, 1.3-4; P = .007). Patients with no prior access attempts had lower predicted mortality (HR, 0.5; 95% CI, 0.3-0.9; P = .02).ConclusionsThe DRIL procedure effectively improves distal perfusion and reverses the symptoms of ARHI while salvaging the access, but the long-term survival of these patients is poor. Given the poor survival, preoperative risk stratification is critical. Patients at high risk for DRIL failure and mortality may be best served with alternate remedial procedures

The Association of Weight loss, Weight status, and Abdominal Obesity with all-cause Mortality in Older Adults

International audienceObjectives: The objectives of this study were to examine whether weight loss, weight status (based on body mass index [BMI] categories), and abdominal obesity (based on waist circumference [WC]) were associated with a 17-year mortality risk in community-dwelling older adults. Methods: Participants were 2,017 community-dwelling adults aged 65 years or above in the longitudinal Enquête de Santé Psychologique-Risques, Incidence et Traitement study. Self-reported weight loss was collected at baseline during face-to-face interviews. Bodyweight (kg), height (m), and WC (cm) were independently measured at the baseline. BMI was categorized as follows: underweight (BMI &#x3c;18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25–29.9 kg/m2), and obese (≥30 kg/m2). Abdominal obesity was defined by a WC of ≥102 cm in men and ≥88 cm in women. Adjusted Cox proportional hazards models were used to examine associations of weight loss, weight status, and abdominal obesity with all-cause mortality. Results: Over 17 years of follow-up (median 15.5 years), 812 participants died. Abdominal obesity compared to nonabdominal obesity was associated with a 49% increased mortality risk (95% confidence interval (CI): 1.22–1.83). However, being overweight (but not obese) was associated with a 20% decreased risk (95% CI: 0.66–0.97) compared to a normal BMI. Gender did not affect these associations. In the whole cohort, self-reported weight loss at baseline was not associated with an increased mortality risk after adjusting for health and lifestyle factors. However, in men, a baseline self-reported recent weight loss of &#x3e;3 kg was associated with a 52% increase in mortality risk (95% CI: 1.05–2.18) in a fully adjusted model. Conclusion: In community-dwelling adults aged ≥65 years, abdominal obesity was strongly associated with increased mortality risk. Being overweight appeared, however, to be protective against mortality. Modest self-reported weight loss was not associated with all-cause mortality in community-dwelling older adults after adjusting for health and lifestyle factors. However, men reporting recent weight loss of more than 3 kg may be at increased risk. The findings of this study support the use of WC, rather than BMI, as a predictor of mortality risk in older adults

Outcomes after redo aortobifemoral bypass for aortoiliac occlusive disease

ObjectivePatients presenting with occluded aortobifemoral (ABF) bypass grafts are managed with a variety of techniques. Redo ABF (rABF) bypass procedures are infrequently performed because of concerns about procedural complexity and morbidity. The purpose of this analysis was to compare midterm results of rABF bypass with those of primary ABF (pABF) bypass for aortoiliac occlusive disease to determine if there are significant differences in outcomes.MethodsA retrospective review was performed of all patients undergoing ABF bypass for occlusive disease between January 2002 and March 2012. A total of 19 patients underwent rABF bypass and 194 received pABF bypass during that period. Data for an indication- and comorbidity-matched case-control cohort of 19 elective pABF bypass patients were collected for comparison to the rABF bypass group. Primary end points included rate of major complications as well as 30-day and all-cause mortality. Secondary end points were amputation-free survival and freedom from major adverse limb events.ResultsThe rABF bypass patients more frequently underwent prior extra-anatomic or lower extremity bypass operations compared with pABF bypass patients (P = .02); however, no difference was found in the incidence of prior failed endovascular iliac intervention (P = .4). By design, indications for the rABF and pABF bypass groups were the same (claudication, n = 6/6 [31.6%]; P = 1; critical limb ischemia, n = 13/13 [78.4%]; P = 1). Aortic access was more frequently by retroperitoneal exposure in the rABF bypass group (n = 13 vs n = 1; P < .0001), and a significantly higher proportion of the rABF bypass patients required concomitant infrainguinal bypass or intraprocedural adjuncts such as profundaplasty (n = 14 vs n = 5; P = .01). The rABF bypass patients experienced greater blood loss (1097 ± 983 mL vs 580 ± 457 mL; P = .02), received more intraoperative fluids (3400 ± 1422 mL vs 2279 ± 993 mL; P = .01), and had longer overall procedure times (408 ± 102 minutes vs 270 ± 48 minutes; P < .0001). Length of stay (days ± standard deviation) was similar (pABF bypass, 11.2 ± 10.4; rABF bypass, 9.1 ± 4.5; P = .7), and no 30-day or in-hospital deaths occurred in either group. Similar rates of major complications occurred in the two groups (pABF bypass, n = 6 [31.6%]; rABF bypass, n = 4 [21.1%]; observed difference, 9.5%; 95% confidence interval, −17.6% to 36.7%; P = .7). Two-year freedom from major adverse limb events (±standard error mean) was 82% ± 9% vs 78% ± 10% for pABF and rABF bypass patients (log-rank, P = .6). Two-year amputation-free survival was 90 ± 9% vs 89 ± 8% between pABF and rABF bypass patients (P = .5). Two-year survival was 91% ± 9% and 90% ± 9% for pABF and rABF bypass patients (P = .8).ConclusionsPatients undergoing rABF bypass have higher procedural complexity compared with pABF bypass as evidenced by greater operative time, blood loss, and need for adjunctive procedures. However, similar perioperative morbidity, mortality, and midterm survival occurred in comparison to pABF bypass patients. These results support a role for rABF bypass in selected patients

Preoperative prediction of spinal cord ischemia after thoracic endovascular aortic repair

ObjectiveSpinal cord ischemia (SCI) is a devastating but potentially preventable complication of thoracic endovascular aortic repair (TEVAR). The purpose of this analysis was to determine what factors predict SCI after TEVAR.MethodsAll TEVAR procedures at a single institution were reviewed for patient characteristics, prior aortic repair history, aortic centerline of flow analysis, and procedural characteristics. SCI was defined as any lower extremity neurologic deficit that was not attributable to an intracranial process or peripheral neuropathy. Forty-three patient and procedural variables were evaluated individually for association with SCI. Those with the strongest relationships to SCI (P < .1) were included in a multivariable logistic regression model, and a stepwise variable elimination algorithm was bootstrapped to derive a best subset of predictors from this model.ResultsFrom 2002 to 2013, 741 patients underwent TEVAR for various indications, and 68 (9.2%) developed SCI (permanent: n = 38; 5.1%). Because of the lack of adequate imaging for centerline analysis, 586 patients (any SCI, n = 43; 7.4%) were subsequently analyzed. Patients experiencing SCI after TEVAR were older (SCI, 72 ± 11 years; no SCI, 65 ± 15 years; P < .0001) and had significantly higher rates of multiple cardiovascular risk factors. The stepwise selection procedure identified five variables as the most important predictors of SCI: age (odds ratio [OR] multiplies by 1.3 per 10 years; 95% confidence interval [CI], 0.9-1.8, P = .06), aortic coverage length (OR multiplies by 1.3 per 5 cm; CI, 1.1-1.6; P = .002), chronic obstructive pulmonary disease (OR, 1.9; CI, 0.9-4.1; P = .1), chronic renal insufficiency (creatinine concentration ≥ 1.6 mg/dL; OR, 1.9; CI, 0.8-4.2; P = .1), and hypertension (defined as chart history or medication; OR, 6.4; CI, 2.6-18; P < .0001). A logistic regression model with just these five covariates had excellent discrimination (area under the receiver operating characteristic curve = .83) and calibration (χ2 = 9.8; P = .28).ConclusionsThis analysis generated a simple model that reliably predicts SCI after TEVAR. This clinical tool can assist decision-making about when to proceed with TEVAR, guide discussions about intervention risk, and help determine when maneuvers to mitigate SCI risk should be implemented

Long-term results of open and endovascular revascularization of superficial femoral artery occlusive disease

BackgroundFirst-line treatment for patients with superficial femoral arterial (SFA) occlusive disease has yet to be determined. This study compared long-term outcomes between primary SFA stent placement and primary femoral-popliteal bypass. Periprocedural patient factors were examined to determine their effect on these results.MethodsAll femoral-popliteal bypasses and SFA interventions performed in consecutive patients with symptoms Rutherford 3 to 6 between 2001 and 2008 were reviewed. Time-dependent outcomes were analyzed using the Kaplan-Meier method and log-rank test. Cox proportional hazards were performed to determine predictors of graft patency. Multivariate analysis was completed to identify patient covariates most often associated with the primary therapy.ResultsA total of 152 limbs in 141 patients (66% male; mean age, 66 ± 22 years) underwent femoral-popliteal bypass, and 233 limbs in 204 patients (49% male; mean age, 70 ± 11 years) underwent SFA interventions. Four-year primary, primary-assisted, and secondary patency rates were 69%, 78%, and 83%, respectively, for bypass patients and 66%, 91%, and 95%, respectively, for SFA interventions. Six-year limb salvage was 80% for bypass vs 92% for stenting (P = .04). Critical limb ischemia (CLI) and renal insufficiency were predictors of bypass failure. Claudication was a predictor of success for SFA stenting. Three-year limb salvage rates for CLI patients undergoing surgery and SFA stenting were 83%. Amputation-free survival at 3 years for CLI patients was 55% for bypass and 59% for SFA interventions. Multivariate predictors (odds ratios and 95% confidence intervals) of covariates most frequently associated with first-line SFA stenting were TransAtlantic Inter-Society Consensus II A and B lesions (5.9 [3.4-9.1], P < .001), age >70 years (2.1 [1.4-3.1], P < .001), and claudication (1.7 [1.1-2.7], P = .01). Regarding bypass as first-line therapy, claudicant patients were more likely to have nondiabetic status (5.6 [3.3-9.4], P < .001), creatinine <1.8 mg/dL (4.6 [1.5-14.9], P = .01), age <70 years (2.7 [CI, 1.6-8.3], P < .001), and presence of an above-knee popliteal artery target vessel (1.9 [CI, 1.1-3.4] P = .02).ConclusionIndication, patient-specific covariates, and anatomic lesion classification have significant association when determining surgeon selection of SFA stenting or femoral-popliteal bypass as first-line therapy. Patients with SFA disease can have comparable long-term results when treatment options are well matched to patient-specific and anatomic characteristics

The use of antimicrobials in italian heavy pig fattening farms

Data on antimicrobial use (AMU) in heavy pig production (&gt;150 kg) are limited. The aim of this study was to investigate the AMU in this production. Data from 2015 were collected for 143 fattening farms. The AMU was estimated through a treatment index per 100 days (TI100) using the defined daily dose animal for Italy (DDDAit). When possible, a comparison with the European Medicines Agency’s defined daily doses for animals (DDDvet) was performed. The median TI100 was 10.7 (range, 0.2–49.5). Group treatments represented 94.6% of overall consumption. The AMU calculated using DDDAit and DDDvet were strongly correlated (ρ = 0.976; p &lt; 0.001). The AMU was negatively correlated with injectables use (ρ = −0.46, p &lt; 0.001) and positively correlated with oral products (ρ = 0.21, p = 0.014), premixes (ρ = 0.26, p = 0.002), and mortality (ρ = 0.18; p = 0.027). Farm size was negatively correlated with AMU (ρ = −0.29, p &lt; 0.001). Smaller farms were more frequently above the median TI100 (odds ratio = 2.3, 95% confidence interval = 1.2–4.7), suggesting that they may have lower biosecurity and management standards. The results of this study should provide useful insights for the development of an Italian monitoring system