Early warning signals for bifurcations embedded in high dimensions.

Recent work has highlighted the utility of methods for early warning signal detection in dynamic systems approaching critical tipping thresholds. Often these tipping points resemble local bifurcations, whose low dimensional dynamics can play out on a manifold embedded in a much higher dimensional state space. In many cases of practical relevance, the form of this embedding is poorly understood or entirely unknown. This paper explores how measurement of the critical phenomena that generically precede such bifurcations can be used to make inferences about some properties of their embeddings, and, conversely, how prior knowledge about the mechanism of bifurcation can robustify predictions of an oncoming tipping event. These modes of analysis are first demonstrated on a simple fluid flow system undergoing a Hopf bifurcation. The same approach is then applied to data associated with the West African monsoon shift, with results corroborated by existing models of the same system. This example highlights the effectiveness of the methodology even when applied to complex climate data, and demonstrates how a well-resolved spatial structure associated with the onset of atmospheric instability can be inferred purely from time series measurements.

Early bladder dysfunction after vesicovaginal fistula repair: A prospective comparative analysis of transvaginal, open, and laparoscopic abdominal approaches.

INTRODUCTION: We aim to compare the clinical and urodynamic profile of lower urinary tract symptoms (LUTS) in patients undergoing laparoscopic, open transabdominal, and laparoscopic transabdominal vesicovaginal fistulae (VVF) repair at 3 months of repair, that is, in early postoperative period. MATERIALS AND METHODS: Fifty-one consecutive patients with endoscopically confirmed VVF were enrolled in our study over 2 years. Malignant fistulae, radiation-induced, and complex fistulae were excluded after cross-sectional imaging. All patients underwent a postoperative assessment for the success of the repair. Then at 3 months, they completed the American Urological Association Symptom Score questionnaire and underwent a dual channel pressure-flow urodynamic study. The results of transvaginal, laparoscopic, and open transabdominal repairs were compared. RESULTS: All patients belonged to the Indian Caucasian race. The mean age was 35.43 ± 6.63 years. Thirty-two patients had supratrigonal and 19 had trigonal fistulae. Laparoscopic transabdominal repair was done in 15 patients, open transabdominal repair in 22 patients, and transvaginal repair in 14 patients. Forty-six patients reported some LUTS at a median follow-up of 5.83 ± 2.37 months postoperatively. Only 18 (35.2%) of these patients had moderate to severe symptoms The postoperative bladder dysfunction rates in open transabdominal, transvaginal and laparoscopic transabdominal groups were 36.4%, 28.6%, and 20%, respectively. Twenty-seven patients (52.9%) had some urodynamic abnormality, that is, small capacity (5), high voiding pressures (14), genuine stress incontinence (3), and poor compliance (3). Bladder capacity was a significant predictor of bladder dysfunction in our patients. CONCLUSIONS: In our study, all three surgical approaches were associated with bladder dysfunction, however, it was the least in the laparoscopic transabdominal approach. Postoperative bladder capacity is a significant predictor of bladder dysfunction.

Health and equity implications of individual adaptation to air pollution in a changing climate.

Future climate change can cause more days with poor air quality. This could trigger more alerts telling people to stay inside to protect themselves, with potential consequences for health and health equity. Here, we study the change in US air quality alerts over this century due to fine particulate matter (PM2.5), who they may affect, and how they may respond. We find air quality alerts increase by over 1 mo per year in the eastern United States by 2100 and quadruple on average. They predominantly affect areas with high Black populations and leakier homes, exacerbating existing inequalities and impacting those less able to adapt. Reducing emissions can offer significant annual health benefits ($5,400 per person) by mitigating the effect of climate change on air pollution and its associated risks of early death. Relying on people to adapt, instead, would require them to stay inside, with doors and windows closed, for an extra 142 d per year, at an average cost of $11,000 per person. It appears likelier, however, that people will achieve minimal protection without policy to increase adaptation rates. Boosting adaptation can offer net benefits, even alongside deep emission cuts. New adaptation policies could, for example: reduce adaptation costs; reduce infiltration and improve indoor air quality; increase awareness of alerts and adaptation; and provide measures for those working or living outdoors. Reducing emissions, conversely, lowers everyone's need to adapt, and protects those who cannot adapt. Equitably protecting human health from air pollution under climate change requires both mitigation and adaptation.

Utilising anterolateral bladder flap to create a continent cutaneous diversion in a patient with pelvic fracture urethral injury.

A male child in the first decade of life presented to us with a history of a pelvic fracture and urethral injury resulting from a road traffic accident 4 months prior. He had previously undergone an exploratory laparotomy and suprapubic cystostomy at another medical centre. He was circumcised and exhibited a substantial urethral defect on the retrograde urethrogram, as well as on the micturating cystourethrogram. Following a careful assessment of the patient's and caregivers' expectations, a continent cutaneous catheterisable channel was planned. This procedure involved the use of an anterolateral bladder flap, and continence was achieved through the creation of a Nissen-type seromuscular invagination. Three months postoperatively, the child remains continent, can easily catheterise the stoma and has resumed his education.

Predicting discrete-time bifurcations with deep learning.

Many natural and man-made systems are prone to critical transitions-abrupt and potentially devastating changes in dynamics. Deep learning classifiers can provide an early warning signal for critical transitions by learning generic features of bifurcations from large simulated training data sets. So far, classifiers have only been trained to predict continuous-time bifurcations, ignoring rich dynamics unique to discrete-time bifurcations. Here, we train a deep learning classifier to provide an early warning signal for the five local discrete-time bifurcations of codimension-one. We test the classifier on simulation data from discrete-time models used in physiology, economics and ecology, as well as experimental data of spontaneously beating chick-heart aggregates that undergo a period-doubling bifurcation. The classifier shows higher sensitivity and specificity than commonly used early warning signals under a wide range of noise intensities and rates of approach to the bifurcation. It also predicts the correct bifurcation in most cases, with particularly high accuracy for the period-doubling, Neimark-Sacker and fold bifurcations. Deep learning as a tool for bifurcation prediction is still in its nascence and has the potential to transform the way we monitor systems for critical transitions.

Clinical and Urodynamic Predictors for Failure of Medical Management with Alpha Blockers in PBNO: A Retrospective Cohort Analysis.

OBJECTIVE: To evaluate the clinical and urodynamic variables that may predict the failure of alpha-blockers in primary bladder neck obstruction (PBNO) patients. Alpha-blockers are useful as a treatment option in patients with PBNO. Nonresponders need to undergo bladder neck incision (BNI). Little is known about the predictive factors determining the success of treatment. MATERIALS AND METHODS: This was a retrospective study, spanning over a period of 8 years. PBNO was diagnosed in the presence of a bladder outlet obstruction index (BOOI) >40 with video-urodynamic evidence of obstruction at the bladder neck. The patients were initially managed with alpha-blockers (alfuzosin and tamsulosin) for 3-6 months, and BNI contemplated when pharmacotherapy failed. The patients with upper tract changes managed with upfront BNI or clean intermittent catheterization were excluded. The data for the international prostate symptom score (IPSS), uroflowmetry, urodynamic studies, and ultrasonography of pre and post-treatment periods were reviewed. Treatment outcomes were defined as complete response (>50% improvement in Qmax and IPSS score) and partial response (30%-50% improvement in Qmax and IPSS score) at 3 or 6 months. RESULTS: Ninety-nine patients were analyzed. 21 patients underwent BNI for the failure of medical management and 31 for recurrence of symptoms at a mean follow-up of 18.8 ± 3.5 months (12-70 months). Independent predictors of failure of pharmacotherapy with alpha-blockers were age (P = .021), Pdet@Qmax (P = .015), and BOOI (P = .019). CONCLUSION: Alpha-blockers are more likely to fail in PBNO in younger patients generating higher voiding pressures and BOOI > 60.

Global beta-diversity of angiosperm trees is shaped by Quaternary climate change.

As Earth's climate has varied strongly through geological time, studying the impacts of past climate change on biodiversity helps to understand the risks from future climate change. However, it remains unclear how paleoclimate shapes spatial variation in biodiversity. Here, we assessed the influence of Quaternary climate change on spatial dissimilarity in taxonomic, phylogenetic, and functional composition among neighboring 200-kilometer cells (beta-diversity) for angiosperm trees worldwide. We found that larger glacial-interglacial temperature change was strongly associated with lower spatial turnover (species replacements) and higher nestedness (richness changes) components of beta-diversity across all three biodiversity facets. Moreover, phylogenetic and functional turnover was lower and nestedness higher than random expectations based on taxonomic beta-diversity in regions that experienced large temperature change, reflecting phylogenetically and functionally selective processes in species replacement, extinction, and colonization during glacial-interglacial oscillations. Our results suggest that future human-driven climate change could cause local homogenization and reduction in taxonomic, phylogenetic, and functional diversity of angiosperm trees worldwide.