Methods For Detecting Early Warnings Of Critical Transitions In Time Series Illustrated Using Simulated Ecological Data

Many dynamical systems, including lakes, organisms, ocean circulation patterns, or financial markets, are now thought to have tipping points where critical transitions to a contrasting state can happen. Because critical transitions can occur unexpectedly and are difficult to manage, there is a need for methods that can be used to identify when a critical transition is approaching. Recent theory shows that we can identify the proximity of a system to a critical transition using a variety of so-called ‘early warning signals’, and successful empirical examples suggest a potential for practical applicability. However, while the range of proposed methods for predicting critical is rapidly expanding, opinions on their practical use differ widely, and there is no comparative study that tests the limitations of the different methods to identify approaching critical transitions using time-series data. Here, we summarize a range of currently available early warning methods and apply them to two simulated time series that are typical of systems undergoing a critical transition. In addition to a methodological guide, our work offers a practical toolbox that may be used in a wide range of fields to help detect early warning signals of critical transitions in time series data.Organismic and Evolutionary Biolog

Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

Comparison of F(ab') versus Fab antivenom for pit viper envenomation: A prospective, blinded, multicenter, randomized clinical trial

BACKGROUND: Crotalidae Polyvalent Immune Fab (Ovine) has been the only antivenom commercially available in the US since 2007 for treatment of Crotalinae envenomation. Late coagulopathy can occur or recur after clearance of Fab antivenom, often after hospital discharge, lasting in some cases more than 2 weeks. There have been serious, even fatal, bleeding complications associated with recurrence phenomena. Frequent follow-up is required, and additional intervention or hospitalization is often necessary. F(ab')2 immunoglobulin derivatives have longer plasma half life than do Fab. We hypothesized that F(ab')2 antivenom would be superior to Fab in the prevention of late coagulopathy following treatment of patients with Crotalinae envenomation. METHODS: We conducted a prospective, double-blind, randomized clinical trial, comparing late coagulopathy in snakebitten patients treated with F(ab')2 with maintenance doses [F(ab')2/F(ab')2], or F(ab')2 with placebo maintenance doses [F(ab')2/placebo], versus Fab with maintenance doses [Fab/Fab]. The primary efficacy endpoint was coagulopathy (platelet count < 150 K/mm(3), fibrinogen level < 150 mg/dL) between end of maintenance dosing and day 8. RESULTS: 121 patients were randomized at 18 clinical sites and received at least one dose of study drug. 114 completed the study. Of these, 11/37 (29.7%) in the Fab/Fab cohort experienced late coagulopathy versus 4/39 (10.3%, p < 0.05) in the F(ab')2/F(ab')2 cohort and 2/38 (5.3%, p < 0.05) in the F(ab')2/placebo cohort. The lowest heterologous protein exposure was with F(ab')2/placebo. No serious adverse events were related to study drug. In each study arm, one patient experienced an acute serum reaction and one experienced serum sickness. CONCLUSIONS: In this study, management of coagulopathic Crotalinae envenomation with longer-half-life F(ab')2 antivenom, with or without maintenance dosing, reduced the risk of subacute coagulopathy and bleeding following treatment of envenomation

A gap analysis on modelling of sea lice infection pressure from salmonid farms. I. A structured knowledge review

Sustainability of aquaculture, an important component of the blue economy, relies in part on ensuring assessment of environmental impact and interactions relating to sea lice dispersing from open pen salmon and trout farms. We review research underpinning the key stages in the sea lice infection process to support modelling of lice on wild salmon in relation to those on farms. The review is split into 5 stages: larval production; larval transport and survival; exposure and infestation of new hosts; development and survival of the attached stages; and impact on host populations. This modular structure allows the existing published data to be reviewed and assessed to identify data gaps in modelling sea lice impacts in a systematic way. Model parameterisation and parameter variation is discussed for each stage, providing an overview of knowledge strength and gaps. We conclude that a combination of literature review, empirical data collection and modelling studies are required on an iterative basis to ensure best practice is applied for sustainable aquaculture. The knowledge gained can then be optimised and applied at regional scales, with the most suitable modelling frameworks applied for the system, given regional limitations

A gap analysis on modelling of sea lice infection pressure from salmonid farms. II. Identifying and ranking knowledge gaps: output of an international workshop

Sea lice are a major health hazard for farmed Atlantic salmon in Europe, and their impact is felt globally. Given the breadth of ongoing research in sea lice dispersal and population modelling, and focus on research-led adaptive management, we brought experts together to discuss research knowledge gaps. Gaps for salmon lice infection pressure from fish farms were identified and scored by experts in sea lice-aquaculture-environment interactions, at an international workshop in 2021. The contributors included experts based in Scotland, Norway, Ireland, Iceland, Canada, the Faroe Islands, England and Australia, employed by governments, industry, universities and non-government organisations. The workshop focused on knowledge gaps underpinning 5 key stages in salmon lice infection pressure from fish farms: larval production; larval transport and survival; exposure and infestation of new hosts; development and survival of the attached stages; and impact on host populations. A total of 47 research gaps were identified; 5 broad themes emerged with 13 priority research gaps highlighted as important across multiple sectors. The highest-ranking gap called for higher quality and frequency of on-farm lice count data, along with better sharing of information across sectors. We highlight the need for synergistic international collaboration to maximise transferable knowledge. Round table discussions through collaborative workshops provide an important forum for experts to discuss and agree research priorities

Commentaries on viewpoint : physiology and fast marathons

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The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

Nutritional value and sensory characteristics of meat eating quality of Australian prime lambs supplemented with pelleted canola and flaxseed oils: fatty acid profiles of muscle and adipose tissues

The effects of canola or flaxseed oil dietary supplementation on Longissimus thoracis et lumborum (LTL) muscle and visceral adipose tissue fatty acid (FA) profiles and meat sensory traits in Australian prime lambs from different breeds were investigated. Sixty lambs were fed one of the following pellet treatments: no oil (Control), 2.5% canola, 5% canola, 2.5% flaxseed and 5% flaxseed, balanced by breed (purebred Merino, and first-cross lambs from Corriedale rams mated to Merino ewes and White Suffolk rams mated to Corriedale ewes). Lambs were individually supplemented daily with 1 kg of oil-enriched wheat-based pellets throughout the 7-week feeding trial, after a 3-week adjustment period and an unlimited access to water and lucerne hay. At the end of the feeding trial, all animals were slaughtered. From each carcass, an LTL muscle sampled at the 12/13th rib interface and a visceral adipose tissue sampled from the vicinity of the liver were taken and subjected to fatty acid analysis. A separate LTL muscle sample was utilised for sensory evaluation of meat eating quality. The inclusion of 5% flaxseed oil significantly decreased n-6/n-3 ratio in both tissues. The muscle from lambs fed 5% oil supplements had higher omega-3 long-chain polyunsaturated FA (n-3 LC-PUFA) contents and reached the claimable health-benefitting value without deleterious sensory effects. The n-3 LC-PUFA component in visceral adipose tissue was negligible. Tissue FA profiles and sensory quality were influenced by lamb breed. There were significant interactions between oil supplementation levels and lamb breed on some visceral adipose FA and meat juiciness. These findings indicate that a combination of dietary manipulation and lamb genetics can be used as an effective management tool to deliver a nutritionally improved n-3 LC-PUFA lamb to consumers

Nonparametric drift-diffusion-jump metrics in the flickering dataset.

<p>(A) Time series of the state variable (resource biomass). (B, F) Conditional variance versus time and biomass respectively. (C, G) Total variance versus time and resource biomass respectively. (D, H) Diffusion versus time and resource biomass respectively. (G, I) Jump intensity versus time and resource biomass respectively.</p