Five-Year Follow-Up from the CoreValve Expanded Use Transcatheter Aortic Valve-in-Surgical Aortic Valve Study.

Transcatheter aortic valve replacement (TAVR) provides an option for extreme-risk patients who underwent reoperation for a failed surgical aortic bioprosthesis. Long-term data on patients who underwent TAVR within a failed surgical aortic valve (TAV-in-SAV) are limited. The CoreValve Expanded Use Study evaluated patients at extreme surgical risk who underwent TAV-in-SAV. Outcomes at 5 years were analyzed by SAV failure mode (stenosis, regurgitation, or combined). Echocardiographic outcomes are site-reported. TAV-in-SAV was attempted in 226 patients with a mean age of 76.7 ± 10.8 years; 63.3% were male, the Society of Thoracic Surgeons predicted risk of mortality score was 9.0 ± 6.7%, and 87.5% had a New York Heart Association classification III or IV symptoms. Most of the failed surgical bioprostheses were stented (81.9%), with an average implant duration of 10.2 ± 4.3 years. The 5-year all-cause mortality or major stroke rate was 47.2% in all patients; 54.4% in the stenosis, 37.6% in the regurgitation, and 38.0% in the combined groups (p = 0.046). At 5 years, all-cause mortality was higher in patients with versus without 30-day severe prosthesis-patient mismatch (51.7% vs 38.3%, p = 0.026). The overall aortic valve reintervention rate was 5.9%; highest in the regurgitation group (12.6%). The mean aortic valve gradient was 14.1 ± 9.8 mm Hg and effective orifice area was 1.57 ± 0.70 at 5 years. Few patients had >mild paravalvular regurgitation at 5 years (5.5% moderate, 0.0% severe). TAV-in-SAV with supra-annular, self-expanding TAVR continues to represent a safe and lasting intermediate option for extreme-risk patients who have appropriate sizing of the preexisting failed surgical valve. Clinical and hemodynamic outcomes were stable through 5 years.

1-Year Outcomes Following Transfemoral Transseptal Transcatheter Mitral Valve Replacement: Intrepid TMVR Early Feasibility Study Results.

BACKGROUND: High surgical risk may preclude mitral valve replacement in many patients. Transcatheter mitral valve replacement (TMVR) using transfemoral transseptal access is a novel technology for the treatment of mitral regurgitation (MR) in high-risk surgical patients. OBJECTIVES: This analysis evaluates 30-day and 1-year outcomes of the Intrepid TMVR Early Feasibility Study in patients with ≥moderate-severe MR. METHODS: The Intrepid TMVR Early Feasibility Study is a multicenter, prospective, single-arm study. Clinical events were adjudicated by a clinical events committee; endpoints were defined according to Mitral Valve Academic Research Consortium criteria. RESULTS: A total of 33 patients, enrolled at 9 U.S. sites between February 2020 and August 2022, were included. The median age was 80 years, 63.6% of patients were men, and mean Society of Thoracic Surgeons Predicted Risk of Mortality for mitral valve replacement was 5.3%. Thirty-one (93.9%) patients were successfully implanted. Median postprocedural hospitalization length of stay was 5 days, and 87.9% of patients were discharged to home. At 30 days, there were no deaths or strokes, 8 (24.2%) patients had major vascular complications and none required surgical intervention, there were 4 cases of venous thromboembolism all successfully treated without sequelae, and 1 patient had mitral valve reintervention for severe left ventricular outflow tract obstruction. At 1 year, the Kaplan-Meier all-cause mortality rate was 6.7%, echocardiography showed ≤mild valvular MR, there was no/trace paravalvular leak in all patients, median mitral valve mean gradient was 4.6 mm Hg (Q1-Q3: 3.9-5.3 mm Hg), and 91.7% of survivors were in NYHA functional class I/II with a median 11.4-point improvement in Kansas City Cardiomyopathy Questionnaire overall summary scores. CONCLUSIONS: The early benefits of the Intrepid transfemoral transseptal TMVR system were maintained up to 1 year with low mortality, low reintervention, and near complete elimination of MR, demonstrating a favorable safety profile and durable valve function.

First-in-Human Multicenter Experience of the Newest Generation Supra-Annular Self-Expanding Evolut FX TAVR System.

BACKGROUND: The latest-generation Evolut FX TAVR system (Medtronic) offers several potential design improvements over its predecessors, but early reported experience has been limited. OBJECTIVES: This study sought to report our multicenter, limited market release, first-in-human experience of transcatheter aortic valve replacement (TAVR) with the Evolut FX system and compare it with a single-center PRO+ (Medtronic) experience. METHODS: From June 27 to September 16, 2022, 226 consecutive patients from 9 US centers underwent transfemoral TAVR with the Evolut FX system for native aortic stenosis (89.4%) or prosthetic valve degeneration (10.6%). Commissural alignment was defined as 0° to 30° between native and FX commissures. Patient, anatomical, and procedural characteristics were retrospectively reviewed, and 30-day clinical and echocardiographic outcomes per Valve Academic Research Consortium-3 definitions were reported. RESULTS: Of 226 patients, 34.1% were low risk, 4% had a bicuspid valve, and 11.5% had a horizontal root (≥60°). Direct Inline sheath (Medtronic) was used in 67.6% and Lunderquist stiff wire (Cook Medical) in 35.4% of cases. Optimal hat marker orientation during deployment was achieved in 98.4%, with commissural alignment in 96.5%. At 30 days, 14.3% mild, 0.9% moderate, and no severe paravalvular leak were observed. Compared with the Evolut PRO+ experience from 1 center, FX had a more symmetrical implantation with shallower depth at the left coronary cusp (P < 0.001), fewer device recaptures (26.1% vs 39.5%; P = 0.004), and improved commissural alignment (96.5% vs 80.2%; P < 0.001). CONCLUSIONS: The Evolut FX system demonstrated favorable 30-day outcomes with a significant improvement over PRO+ in achieving commissural alignment, fewer device recaptures, and more symmetrical implantation. These features may benefit younger patients undergoing TAVR with the supra-annular, self-expanding valve, where lifetime management would be important.

Clinical Predictors of Mortality and Heart Failure Hospitalization in Patients With Severe Tricuspid Regurgitation.

Background: There is an incomplete understanding of the predictors of morbidity and mortality in patients with severe tricuspid regurgitation (TR). This study sought to identify key risk factors for all-cause mortality and heart failure (HF) hospitalization among patients with severe TR. Methods: Patients with severe TR were identified from 2 centers, Oregon Health & Science University and Abrazo Health, from January 01, 2016 to December 31, 2018. Patients with any concomitant severe valvular diseases or prior valvular intervention were excluded. Multivariable regression was utilized to identify demographic, clinical, and echocardiographic variables independently associated with all-cause mortality or HF hospitalization. Results: 435 patients with severe TR were followed for a median of 2.8 years. The mean age of the population was 66.9 ± 18.5 years and 58% were female. All-cause mortality was identified in 20.5% of the population. Of the cohort, 35.4% of patients were hospitalized for HF. Isolated tricuspid valve intervention was performed in 2.5% of patients. Independent predictors of all-cause mortality included history of solid tumor (odds ratio [OR] 6.6, 95% confidence interval [CI] 2.1-19.1, p = 0.001), history of peripheral artery disease (OR 3.5, 95% CI 1.2-9.4, p = 0.013), and elevated international normalized ratio in the absence of anticoagulation (OR 1.9, 95% CI 1.2-3.2, p = 0.008). Predictors of HF hospitalization included history of diabetes mellitus (OR 2.2, 95% CI 1.1-4.0, p = 0.014) and history of reduced left ventricular ejection fraction (OR 5.7, 95% CI 2.9-11.7, p < 0.0001). Conclusions: Severe untreated TR is associated with high mortality and frequent HF hospitalizations. Understanding predictors of these outcomes is important to identify patients who may benefit from early tricuspid valve intervention to help improve outcomes in this patient population.

Rapid topographic growth of the Taiwan orogen since ~1.3-1.5 Ma.

We present the first paleotopographic reconstruction of Taiwan by measuring the hydrogen isotope composition of leaf waxes (δ2HnC29) preserved in 3-Ma and younger sediments of the southern Coastal Range. Plant leaf waxes record the δ2H of precipitation during formation, which is related to elevation. Leaf waxes produced across the orogen are transported and deposited in adjacent sedimentary basins, providing deep-time records of the source elevation of detrital organic matter. δ2HnC29 exported from the southern Taiwan orogen decreased by more than 40‰ since ~1.3-1.5 Ma, indicating an increase of >2 kilometers in the organic source elevation. The increase in organic source elevation is best explained by rapid surface uplift of the southern Central Range at around ~1.3-1.5 Ma and indicates that this part of the orogen was characterized by maximum elevations of at least 3 km at this time. Further increase in organic source elevation from ~0.85 to ~0.3 Ma indicates continued topographic growth to modern elevations.

Simulating the Commercial Implementation of Gene-Editing for Influenza A Virus Resistance in Pigs: An Economic and Genetic Analysis.

The development of swine Influenza A Virus resistance along with genetic technologies could complement current control measures to help to improve animal welfare standards and the economic efficiency of pig production. We have created a simulation model to assess the genetic and economic implications of various gene-editing methods that could be implemented in a commercial, multi-tiered swine breeding system. Our results demonstrate the length of the gene-editing program was negatively associated with genetic progress in commercial pigs and that the time required to reach fixation of resistance alleles was reduced if the efficiency of gene-editing is greater. The simulations included the resistance conferred in a digenic model, the inclusion of genetic mosaicism in progeny, and the effects of selection accuracy. In all scenarios, the level of mosaicism had a greater effect on the time required to reach resistance allele fixation and the genetic progress of the herd than gene-editing efficiency and zygote survival. The economic analysis highlights that selection accuracy will not affect the duration of gene-editing and the investment required compared to the effects of gene-editing-associated mosaicism and the swine Influenza A Virus control strategy on farms. These modelling results provide novel insights into the economic and genetic implications of targeting two genes in a commercial pig gene-editing program and the effects of selection accuracy and mosaicism.

Propensity-Matched 1-Year Outcomes Following Transcatheter Aortic Valve Replacement in Low-Risk Bicuspid and Tricuspid Patients.

OBJECTIVES: The aim of this study was to compare 1-year outcomes after transcatheter aortic valve replacement (TAVR) in low surgical risk patients with bicuspid aortic stenosis to patients with tricuspid aortic stenosis. BACKGROUND: The pivotal TAVR trials excluded patients with bicuspid aortic valves. The Low Risk Bicuspid Study 30-day primary endpoint of death or disabling stroke was 1.3%. METHODS: The Low Risk Bicuspid Study is a prospective, single-arm, TAVR trial that enrolled patients from 25 U.S. sites. A screening committee confirmed bicuspid anatomy and valve classification on computed tomography using the Sievers classification. Valve sizing was by annular measurements. An independent clinical events committee adjudicated all serious adverse events, and an independent core laboratory assessed all echocardiograms. The 150 patients from the Low Risk Bicuspid Study were propensity matched to the TAVR patients in the randomized Evolut Low Risk Trial using the 1:1 5- to-1-digit greedy method, resulting in 145 pairs. RESULTS: All-cause mortality or disabling stroke at 1 year was 1.4% in the bicuspid and 2.8% in the tricuspid group (P = 0.413). A pacemaker was implanted in 16.6% of bicuspid and 17.9% of tricuspid patients (P = 0.741). The effective orifice area was similar between groups at 1 year (2.2 ± 0.7 cm2 vs 2.3 ± 0.6 cm2, P = 0.677) as was the mean gradient (8.7 ± 3.9 mm Hg vs 8.5 ± 3.1 mm Hg, P = 0.754). Fewer patients in the bicuspid group had mild or worse paravalvular leak (21.3% vs 42.6%, P < 0.001). CONCLUSIONS: There were no significant differences in clinical or forward flow hemodynamic outcomes between the propensity-matched groups at 1 year.

Market Intelligence and Incentive-Based Trait Ranking for Plant Breeding: A Sweetpotato Pilot in Uganda.

Crop breeding programs must accelerate crop improvement, spur widespread adoption of new varieties and increase variety turnover they are to meet the diverse needs of their clients. More comprehensive quantitative approaches are needed to better inform breeding programs about the preferred traits among farmers and other actors. However, the ability of current breeding programs to meet the demands of their clients is limited by the lack of insights about value chain actor preference for individual or packages of traits. Ranking traits based on monetary incentives, rather than subjective values, represents a more comprehensive, consistent, and quantitative approach to inform breeding programs. We conducted a large pilot in Uganda to assess the implementation of a novel approach to trait ranking, using a uniquely large sample of diverse sweetpotato value chain actors. We found meaningful differences in trait ranking and heterogeneity among different actors using this approach. We also show our approach's effectiveness at uncovering unmet demand for root quality traits and at characterizing the substantial trait demand heterogeneity among value chain players. Implementing this approach more broadly for sweetpotato and other crops would increase the effectiveness of breeding programs to improve food security in developing countries.

Modeling suggests gene editing combined with vaccination could eliminate a persistent disease in livestock.

Recent breakthroughs in gene-editing technologies that can render individual animals fully resistant to infections may offer unprecedented opportunities for controlling future epidemics in farm animals. Yet, their potential for reducing disease spread is poorly understood as the necessary theoretical framework for estimating epidemiological effects arising from gene-editing applications is currently lacking. Here, we develop semistochastic modeling approaches to investigate how the adoption of gene editing may affect infectious disease prevalence in farmed animal populations and the prospects and time scale for disease elimination. We apply our models to the porcine reproductive and respiratory syndrome (PRRS), one of the most persistent global livestock diseases to date. Whereas extensive control efforts have shown limited success, recent production of gene-edited pigs that are fully resistant to the PRRS virus have raised expectations for eliminating this deadly disease. Our models predict that disease elimination on a national scale would be difficult to achieve if gene editing was used as the only disease control. However, from a purely epidemiological perspective, disease elimination may be achievable within 3 to 6 y, if gene editing were complemented with widespread and sufficiently effective vaccination. Besides strategic distribution of genetically resistant animals, several other key determinants underpinning the epidemiological impact of gene editing were identified.

Contemporary Management of Abdominal Aortic Aneurysms.

PURPOSE OF REVIEW: Abdominal aortic aneurysms (AAA) can carry extremely high mortality rates and most will only present with symptoms with impending rupture. We present an overview of management of this disease process starting with screening, to medical management, surveillance and treatment options currently available, as well as those being studied for future use. RECENT FINDINGS: Screening has been proven to reduce the mortality rate. There still remains a paucity of data to support medical therapies to help mitigate the rate of aneurysm growth and prevent rupture. However, on the topic of repair, there have been advancements in endovascular devices which have broadened the scope of treatment for patients with anatomy not amenable to standard endovascular repair or those who are not suitable candidates for open surgical repair. Appropriate surveillance, risk factor modification, and operative repair, when indicated, are the cornerstones of contemporary management of AAAs. Advancements in endovascular technologies have allowed us to treat more patients. Further research is warranted on non-operative medical therapies.

Outcomes in Patients With Asymptomatic Aortic Stenosis (from the Evolut Low Risk Trial).

Transcatheter aortic valve implantation (TAVI) has comparable outcomes with surgical aortic valve replacement (SAVR) in symptomatic patients with severe aortic stenosis, including those at low risk for surgery. Less is known about TAVI outcomes in asymptomatic patients. This analysis compares clinical, hemodynamic, and quality of life (QOL) outcomes after TAVI or SAVR for low-risk asymptomatic patients. The randomized Evolut Low Risk trial enrolled asymptomatic patients treated with TAVI (n = 76) and SAVR (n = 62). New York Heart Association functional class I identified patients without symptoms. Clinical outcomes, echocardiographic findings, and QOL in both groups were compared 30 days and 12 months after AVR. Asymptomatic patients had a mean Society of Thoracic Surgeons score of 1.7 ± 0.6, 73% were men, and mean age was 74.2 ± 5.8 years. The composite end point of all-cause mortality or disabling stroke was similar at 12 months in patients with TAVI (1.3%) and SAVR (6.5%; p = 0.11), although patients with SAVR tended to have higher rates of all-cause mortality (4.8%) compared with patients with TAVI (0.0%, p = 0.05). Patients with TAVI had lower mean aortic valve gradients (8.1 ± 3.2 mm Hg) and larger mean effective orifice area (2.3 ± 0.6 mm Hg) than patients with SAVR (10.8 ± 3.8; p <0.001 and 1.9 ± 0.6; p = 0.001, respectively), and showed significant improvement in Kansas City Cardiomyopathy Questionnaire scores from baseline to 30 days (∆12.1 ± 23.6; p <0.001), whereas patients with SAVR did not (∆2.2 ± 20.3; p = 0.398). Patients with TAVI and SAVR had a significant improvement in QOL by 12 months compared with baseline. In conclusion, low risk asymptomatic patients with severe aortic stenosis who underwent TAVI had comparable clinical outcomes to SAVR, with superior valve performance and faster QOL improvement.

30-Day Outcomes Following Transfemoral Transseptal Transcatheter Mitral Valve Replacement: Intrepid TMVR Early Feasibility Study Results.

OBJECTIVES: The aim of this study was to evaluate outcomes of transcatheter mitral valve replacement (TMVR) with transfemoral access in patients at prohibitive or high surgical risk. BACKGROUND: Prohibitive surgical risk may preclude mitral valve replacement surgery in some patients. The investigational Intrepid TMVR system has previously been evaluated using transapical access for delivery of a self-expanding bioprosthetic valve. METHODS: This prospective, multicenter, nonrandomized early feasibility study evaluated the safety and performance of the Intrepid valve using transfemoral access enabling transseptal delivery in patients with moderate to severe or severe symptomatic mitral regurgitation at high surgical risk. Candidacy was determined by heart teams, with approval by a central screening committee. Echocardiographic data were evaluated by an independent core laboratory. Clinical events were adjudicated by a clinical events committee. RESULTS: Fifteen patients were enrolled at 6 sites from February 2020 to May 2021. The median age was 80 years, and median Society of Thoracic Surgeons Predicted Risk of Mortality was 4.7%; 87% of patients were men, and 53% had undergone prior sternotomy. Fourteen implants were successful. One patient was converted to surgery during the index procedure. Patients stayed a median of 5 days postprocedure. There were 6 access site bleeds (40%) and 11 iatrogenic atrial septal defect closures (73%). At 30 days, there were no deaths, strokes, or reinterventions. All patients undergoing implantation had trace or no valvular or paravalvular mitral regurgitation, and the mean gradient was 4.7 mm Hg (IQR: 3.0-6.7 mm Hg). CONCLUSIONS: Thirty-day results from the Intrepid transfemoral TMVR early feasibility study demonstrate excellent valve function and no mortality or stroke. Additional patients and longer follow-up are needed to confirm these findings. ([The Early Feasibility Study of the Intrepid™ TMVR Transseptal System]; NCT02322840).

Fabrication and Characterization of Tissue-Mimicking Phantoms for Ultrasound-Guided Cannulation Training.

Tissue-mimicking materials (TMMs) have been investigated and used for decades as imaging phantoms in various medical applications. They are designed and fabricated to replicate certain biological tissue characteristics, a process often dictated by the target application. Moreover, TMMs have been utilized in some medical procedural training requiring the use of imaging modalities. One potential application for TMMs is ultrasound-guided cannulation training. Cannulation is a procedure that requires a level of dexterity to gain vascular access using ultrasound guidance while avoiding complications like vessel laceration and bleeding. However, an ideal phantom for this application is yet to be developed. This work investigates the development and characterization of high-fidelity phantoms for cannulation training. The mechanical (shore hardness, elastic modulus, and needle-interaction forces) and acoustic (B-mode ultrasound scans) properties of candidate materials were quantitatively compared with biological tissue. The evaluated materials included ballistic gel, plasticized polyvinyl chloride (PVC), silicone, gelatin, agar, and polyvinyl alcohol (PVA)- cryogel. Mechanical testing demonstrated that each material could replicate the Shore hardness and elasticity characteristics of different biological tissues (skin, fat, and muscle), with PVA and PVC showing tunability by varying composition or fabrication processes. Shore hardness (OO-range) for PVA ranged between 6.3 ± 1.0 to 59.3 ± 2.6 and PVC from 4.8 ± 0.7 to 14.6 ± 0.8. Ultrasound scans of PVA were the closest to human scans, both qualitatively (based on experts' opinion) and quantitatively (based on pixel intensity measurements). Modified mixtures of PVA are found to best serve as high-fidelity cannulation phantoms. Alternatively, PVC can be used to avoid troublesome fabrication processes of PVA.

Predicting paravalvular leak after transcatheter mitral valve replacement using commercially available software modeling.

BACKGROUND: There is limited data identifying patients at risk for significant mitral regurgitation (MR) after transcatheter mitral valve replacement (TMVR). We hypothesized that software modeling based on computed tomography angiography (CTA) can predict the risk of moderate or severe MR after TMVR. METHODS: 58 consecutive patients underwent TMVR at two institutions, including 31 valve-in-valve, 16 valve-in-ring, and 11 valve-in-mitral annular calcification. 12 (20%) patients developed moderate or severe MR due to paravalvular leak (PVL). RESULTS: The software model correctly predicted 8 (67%) patients with significant PVL, resulting in sensitivity of 67%, specificity 96%, positive predictive value 89%, and negative predictive value 86%. There was excellent agreement between CTA readers using software modeling to predict PVL (kappa 0.92; p < 0.01). On univariate analysis, CTA predictors of moderate or severe PVL included presence of a gap between the virtual valve and mitral annulus on the software model (OR 48; p < 0.01), mitral annular area (OR 1.02; p 0.01), and % valve oversizing (OR 0.9; p 0.01). On multivariate analysis, only presence of a gap on the software model remained significant (OR 36.8; p < 0.01). CONCLUSIONS: Software modeling using pre-procedural CTA is a straightforward method for predicting the risk of moderate and severe MR due to PVL after TMVR.

Mantle fluids associated with crustal-scale faulting in a continental subduction setting, Taiwan.

We report noble gas signatures of groundwater, hot springs, and bedrock samples from a major fault system that separates regional-scale blocks of accreted, continental materials in southern Taiwan. Despite the continental setting, the isotopic signatures argue for the presence of mantle derived fluids, suggesting that the active fault system is deep-seated. This is consistent with deep, non-volcanic tremors identified in the same area. We speculate that the mantle fluids are escaping along a crustal-scale fault marked by clusters of non-volcanic tremors directly beneath the southern Central Range. The evidence of these tremors and electrical conductivity anomalies along the strike of the fault recognized previously correlated up dip with the surface trace of a major active fault support the hypothesis.

Intensive care implications of epidemic thunderstorm asthma.

OBJECTIVE: To investigate the environmental precipitants, treatment and outcome of critically ill patients affected by the largest and most lethal reported epidemic of thunderstorm asthma. DESIGN, SETTING AND PARTICIPANTS: Retrospective multicentre observational study. Meteorological, airborne particulate and pollen data, and a case series of 35 patients admitted to 15 intensive care units (ICUs) due to the thunderstorm asthma event of 21-22 November 2016, in Victoria, Australia, were analysed and compared with 1062 total ICU-admitted Australian patients with asthma in 2016. MAIN OUTCOME MEASURES: Characteristics and outcomes of total ICU versus patients with thunderstorm asthma, the association between airborne particulate counts and storm arrival, and ICU resource utilisation. RESULTS: All 35 patients had an asthma diagnosis; 13 (37%) had a cardiac or respiratory arrest, five (14%) died. Compared with total Australian ICU-admitted patients with asthma in 2016, patients with thunderstorm asthma had a higher mortality (15% v 1.3%, P < 0.001), were more likely to be male (63% v 34%, P < 0.001), to be mechanically ventilated, and had shorter ICU length of stay in survivors (median, 31.8 hours [interquartile range (IQR), 14.8-43.6 hours] v 40.7 hours [IQR, 22.3-75.1 hours]; P = 0.025). Patients with cardiac arrest were more likely to be born in Asian or subcontinental countries (5/10 [50%] v 4/25 [16%]; relative risk, 3.13; 95% CI, 1.05-9.31). A temporal link was demonstrated between airborne particulate counts and arrival of the storm. The event used 15% of the public ICU beds in the region. CONCLUSION: Arrival of a triggering storm is associated with an increase in respirable airborne particles. Affected critically ill patients are young, have a high mortality, a short duration of bronchospasm, and a prior diagnosis of asthma is common.

Complexity of animal breeding choice making.

The last decades of developments in animal breeding, genetics, genomics and data recording technologies have allowed the evaluation of larger numbers of animal and animal traits than ever before. This should help make animal breeding choices more informed, but it also makes them far more complex. This complexity may be overwhelming farmers, thus compromising realization of potential genetic gain in livestock industries. However, the effect of complexity of animal breeding choices on farmers' selection of animals has received very little theoretical consideration to date. This paper reviews the theoretical principles of complex decisions, contextualizes the findings to the field of animal breeding, and analyses how farmers and the animal breeding industry are currently dealing with complexity. According to the findings of the analyses of complex decisions in other fields, the complexity of animal breeding choices is likely to lead to farmers using conscious or unconscious simplifying strategies (heuristics) to handle such complexity. When these heuristics are ineffective, poor selection decisions and a potential loss of genetic progress can be expected. Further, studies using survey experiments to understand farmer behaviour and selection preferences may be compromised by the complexity of the survey´s choice tasks. Thus, while many animal breeding industries recognize the complexity of animal breeding choices for farmers and attempts are made to assist farmers in their choice making, the effectiveness of these attempts is not well quantified and understood. We discuss three areas of research that could be key to disentangling how, and by how much, animal breeding choice complexity affects farmers' decisions.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors.

BACKGROUND: A multidisciplinary collaboration investigated the world's largest, most catastrophic epidemic thunderstorm asthma event that took place in Melbourne, Australia, on Nov 21, 2016, to inform mechanisms and preventive strategies. METHODS: Meteorological and airborne pollen data, satellite-derived vegetation index, ambulance callouts, emergency department presentations, and data on hospital admissions for Nov 21, 2016, as well as leading up to and following the event were collected between Nov 21, 2016, and March 31, 2017, and analysed. We contacted patients who presented during the epidemic thunderstorm asthma event at eight metropolitan health services (each including up to three hospitals) via telephone questionnaire to determine patient characteristics, and investigated outcomes of intensive care unit (ICU) admissions. FINDINGS: Grass pollen concentrations on Nov 21, 2016, were extremely high (>100 grains/m3). At 1800 AEDT, a gust front crossed Melbourne, plunging temperatures 10°C, raising humidity above 70%, and concentrating particulate matter. Within 30 h, there were 3365 (672%) excess respiratory-related presentations to emergency departments, and 476 (992%) excess asthma-related admissions to hospital, especially individuals of Indian or Sri Lankan birth (10% vs 1%, p<0·0001) and south-east Asian birth (8% vs 1%, p<0·0001) compared with previous 3 years. Questionnaire data from 1435 (64%) of 2248 emergency department presentations showed a mean age of 32·0 years (SD 18·6), 56% of whom were male. Only 28% had current doctor-diagnosed asthma. 39% of the presentations were of Asian or Indian ethnicity (25% of the Melbourne population were of this ethnicity according to the 2016 census, relative risk [RR] 1·93, 95% CI 1·74-2·15, p <0·0001). Of ten individuals who died, six were Asian or Indian (RR 4·54, 95% CI 1·28-16·09; p=0·01). 35 individuals were admitted to an intensive care unit, all had asthma, 12 took inhaled preventers, and five died. INTERPRETATION: Convergent environmental factors triggered a thunderstorm asthma epidemic of unprecedented magnitude, tempo, and geographical range and severity on Nov 21, 2016, creating a new benchmark for emergency and health service escalation. Asian or Indian ethnicity and current doctor-diagnosed asthma portended life-threatening exacerbations such as those requiring admission to an ICU. Overall, the findings provide important public health lessons applicable to future event forecasting, health care response coordination, protection of at-risk populations, and medical management of epidemic thunderstorm asthma. FUNDING: None.