Method For Long-term Monitoring Research Articles

Functional maturation and longitudinal imaging of intraportal neonatal porcine islet grafts in genetically diabetic pigs

Allogeneic intraportal islet transplantation (ITx) has become an established treatment for patients with poorly controlled type 1 diabetes. However, the loss of viable beta-cell mass after transplantation remains a major challenge. Therefore, noninvasive imaging methods for long-term monitoring of the transplant fate are required. In this study, [68Ga]Ga-DOTA-exendin-4 positron emission tomography/computed tomography (PET/CT) was used for repeated monitoring of allogeneic neonatal porcine islets (NPI) after intraportal transplantation into immunosuppressed genetically diabetic pigs. NPI transplantation (3.3000-15.0000 islet equivalents per kg body weight) led to a reduced need for exogenous insulin therapy and finally normalization of blood glucose levels in 3 out of 4 animals after 5 to 10 weeks. Longitudinal PET/CT measurements revealed a significant increase in standard uptake values in graft-bearing livers. Histologic analysis confirmed the presence of well-engrafted, mature islet clusters in the transplanted livers. Our study presents a novel large animal model for allogeneic intraportal ITx. A relatively small dose of NPIs was sufficient to normalize blood glucose levels in a clinically relevant diabetic pig model. [68Ga]Ga-DOTA-exendin-4 PET/CT proved to be efficacious for longitudinal monitoring of islet transplants. Thus, it could play a crucial role in optimizing ITx as a curative therapy for type 1 diabetes.

A large scale temporal and spatial environmental DNA biodiversity survey of marine vertebrates in Brazil following the Fundão tailings dam failure

Seawater contains a wealth of genetic information, representing the biodiversity of numerous species residing within a particular marine habitat. Environmental DNA (eDNA) metabarcoding offers a cost effective, non-destructive method for large scale monitoring of environments, as diverse taxonomic groups are detected using metabarcoding assays. A large-scale eDNA monitoring program of marine vertebrates was conducted across three sampling seasons (Spring 2018, Autumn 2019; Spring 2019) in coastal waters of Brazil. The program was designed to investigate eDNA as a testing method for long term monitoring of marine vertebrates following the Fundão tailings dam failure in November 2015. While no baseline samples were available prior to the dam failure there is still value in profiling the taxa that use the impacted area and the trajectory of recovery. A total of 40 sites were sampled around the mouths of eight river systems, covering approximately 500 km of coastline. Metabarcoding assays targeting the mitochondrial genes 16S rRNA and COI were used to detect fish, marine mammals and elasmobranchs. We detected temporal differences between seasons and spatial differences between rivers/estuaries sampled. Overall, the largest eDNA survey in Brazil to date revealed 69 families from Class Actinopterygii (fish), 15 species from Class Chondrichthyes (sharks and rays), 4 species of marine and estuarine mammals and 23 species of conservation significance including 2 species of endangered dolphin. Our large-scale study reinforces the value eDNA metabarcoding can bring when monitoring the biodiversity of coastal environments and demonstrates the importance of collection of time-stamped environmental samples to better understand the impacts of anthropogenic activities.

What happens in the shadows - Influence of seasonal and non-seasonal dynamics on domoic acid monitoring in the Monterey Bay upwelling shadow

Domoic acid produced by toxigenic Pseudo-nitzschia species is the main toxin threat from harmful algal blooms in Monterey Bay and the larger California Current region on the West Coast of the United States. Toxin monitoring in Monterey Bay includes a long-running time series of weekly measurements of domoic acid from water samples, sentinel mussels, and solid phase adsorption toxin tracking (SPATT) at the Santa Cruz Municipal Wharf (SCW). The SCW sampling site is unusual because of its position in the Monterey Bay upwelling shadow in the north bay. The upwelling shadow circulation pattern has been previously characterized as a bloom incubator for dinoflagellates, but it has not yet been analyzed in the context of long-term monitoring methods. In data collected from the SCW from 2012 - 2020, domoic acid from water samples and sentinel mussels had a different temporal distribution than domoic acid from SPATT. Here we explore the discrepancy through a seasonal and non-seasonal analysis including physical oceanography of the region. Results show that domoic acid from water samples and sentinel mussels are related to seasonal upwelling and Pseudo-nitzschia blooms. Domoic acid monitored by SPATT, on the other hand, is correlated to anomalous upwelling and warmer than usual temperatures during the relaxation season. This work builds on previous analyses of the SCW time series and contributes to understanding of the circulation of dissolved toxin in the environment. Results lend rationale for the continuation of rigorous domoic acid monitoring in Monterey Bay and encourage stakeholders to consider local physical dynamics when interpreting toxin monitoring data.

Conservation assessment based on large-scale monitoring of eDNA: Application to freshwater mussels

Environmental DNA (eDNA) analysis allows efficient surveys of freshwater species and is being increasingly used. However, because different authors use different methods, eDNA data cannot easily be summarised for a global overview. One promising approach is to standardise methods for long-term monitoring. Standardised eDNA metabarcoding methods have been implemented in France for an elusive group: freshwater bivalves. All French bivalve species can be detected and identified at each sampling site. Here, we analyse this comprehensive dataset (280 sites across all France; 40 species) to investigate detection probabilities, infer species distributions and reassess conservation status, and finally examine community patterns (richness) and their determinants.Our method gave over 95 % probability of detection for most species. Species distributions inferred from eDNA sampling were compared with currently known distributions. Four invasive species and one species of conservation concern were found outside their known range. Others were found in a surprisingly small number of localities, although they are currently thought to be widespread and not of conservation concern. Indeed, the databases currently used to determine conservation status are biased by the inclusion of old data, mainly based on shell records only, and may include misidentified species. The main drivers of species richness were latitude and distance from the spring. Co-occurrence of species was investigated for the first time. The results highlight the valuable data that eDNA analysis can provide when used on a large scale, for monitoring and ecological studies, as well as providing improved species distributions, which are essential for conservation policymaking.

A Long-Term Monitoring Method of Corrosion Damage of Prestressed Anchor Cable

Based on high-stress characteristics of prestressed anchor cables, this paper develops an axial-distributed testing method to test corrosion damage of prestressed anchor cables. The positioning accuracy and corrosion range of an axial-distributed optical fiber sensor is studied, and its mathematical model between corrosion mass loss and axial fiber strain is established. The experimental results show that the fiber strain from an axial-distributed sensor enables one to reflect the corrosion rate along a prestressed anchor. Moreover, it has a greater sensitivity when an anchored cable has a higher stress. The mathematical model between corrosion mass loss and axial fiber strain is determined to be ε=4723.64ρ+2592.95. The corrosion location along the anchor cable is characterized by axial fiber strain. Therefore, this work provides an insight for cable corrosion.

Long-term monitoring method for tunnel structure transformation using a 3D light detection and ranging equipped in a mobile robot

This study proposes a long-term health monitoring method for tunnel structure transformation using a 3D light detection and ranging (LiDAR) equipped in a mobile robot. The proposed method comprised two phases: 3D point cloud maps (PCMs) generation and health indicators (HIs) extraction at the same location for the long-term structure transformation inspection. First, the 3D point cloud data (PCD) and six-degree-of-freedom acceleration and gyration of a mobile robot were measured during periodic inspection of tunnel structures using the 3D LiDAR and an inertial measurement unit. This information was combined to generate a 3D PCM by utilizing tightly coupled LiDAR inertial odometry. This procedure could be repeated to inspect tunnel structure transformation at patrol inspection in a long term. 3D PCMs measured during period inspection were then registered to extract a 3D PCD at the location of the first measurement. Hence, an iterative closest point method with edge features was executed to register periodic PCD measurements. Second, 3D PCD in predefined locations were extracted at every measurement. These PCD were used to extract features that are highly correlated to the inner wall and ground of the tunnel structure to obtain five HIs representing their health conditions. These HIs were then employed to evaluate the structural health of the tunnel. Field experiments were conducted to demonstrate the effectiveness of the proposed method in buildings and tunnels. The proposed method outperformed other 3D PCM methods, especially in structures with few features such as tunnels and corridors. A systematic analysis of the experimental results also revealed that the proposed method ensures the accuracy and robustness of HIs extraction at the same location, confirming the feasibility of long-term inspection. The proposed inspection method for tunnel structures and embedded mobile robot system provides a cost-effective and autonomous solution for infrastructure health monitoring.

基于自然的碳达峰、碳中和解决方案:关键议题

PDF HTML阅读 XML下载 导出引用 引用提醒 基于自然的碳达峰、碳中和解决方案:关键议题 DOI: 10.5846/stxb202204281179 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 宁夏回族自治区重点研发计划项目(2021BEG03019) Nature-based solutions for carbon peaking and carbon neutrality goals: Key issues Author: Affiliation: Fund Project: Key Research and Development Program of Ningxia (CN)(2021BEG03019) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:实现碳达峰、碳中和是我国生态文明建设的重点战略方向。按照"目标设计-要素布局-方案实施"的基本逻辑,可以对碳达峰、碳中和的工作要点进行系统梳理。基于自然的解决方案(Nature-based Solutions, NbS)是国际社会普遍认可的生态恢复前沿理念,具备可持续性、系统性、尺度性、适应性四方面核心特质,能够有效回应"双碳"目标的工作要求。碳达峰、碳中和与NbS在目标导向和实践思路上高度契合,二者均以可持续发展为主要目标,NbS八项实施准则亦能够为"双碳"工作的积极推进提供全面系统的行动框架。结合NbS实施准则,具体提出基于自然的碳达峰、碳中和八大关键议题:(1)统筹减污降碳协同增效的政策体系;(2)强化尺度级联的传导机制;(3)构建基于自然的固碳途径;(4)完善多元化的碳汇交易;(5)兼顾社会公平的参与机制;(6)促进基于权衡的路径选择;(7)创新动态连续的监测手段;(8)推动NbS在"双碳"领域主流化,以期支撑国家碳达峰、碳中和可持续解决方案的落实。 Abstract:Goals of peak carbon dioxide emissions and carbon neutrality are the key strategic direction for construction of an ecological civilization. Based on the principle of "goals setting, system element layout, and solution strategies implementation", this paper summarized the key points to achieve peak carbon dioxide emissions and carbon neutrality goals. As a cutting-edge concept, Nature-based Solutions (NbS) has been widely recognized by the international community. The core characteristics of sustainability, systematization, scale and adaptability of NbS can effectively promote the achievement of peak carbon dioxide emissions and carbon neutrality goals. As both taking sustainable development as the main goal, NbS is highly compatible with the goals of peak carbon dioxide emissions and carbon neutrality in goal orientation and thinking of practice. Furthermore the eight criteria of NbS can also provide a comprehensive and systematic framework for the active promotion of the goals of peak carbon dioxide emissions and carbon neutrality. Combined with the NbS criteria, eight issues are specifically proposed: (1) coordinating policy system for synergy of pollution reduction and carbon reduction; (2) strengthening the mechanism of information transmission in different scales; (3) building a nature-based pathway to carbon sequestration; (4) improving diversified carbon sink trading; (5) formulating participation rules that take into account social equity; (6) promoting path selection based on trade-offs; (7) innovating dynamic and long-term monitoring methods; and (8) promoting the mainstreaming of NbS in field of peak carbon dioxide emissions and carbon neutrality. 参考文献 相似文献 引证文献

Integrating complementary survey methods to estimate catches in Norway’s complex marine recreational hook-and-line fishery

Abstract Marine recreational fishing is popular in Norway, but current estimates of the catches by resident and tourist anglers are lacking due to several challenges, in particular Norway’s long and intricate coastline with no defined access points and the large tourist fishery. To test methods for long-term monitoring of boat-based marine recreational anglers, estimate their catches, and characterize the fishery, we conducted a roving creel survey based on a novel spatial sampling frame and a survey of tourist fishing businesses in Troms and Hordaland County. These surveys showed that cod (Gadus morhua) and saithe (Pollachius virens) dominated the catches in Troms, while mackerel (Scomber scombrus) and saithe dominated the catches in Hordaland. The estimated total annual harvest of cod by all marine recreational anglers was 2 160 tonnes (relative standard error, or RSE 44%) in Troms and 73 tonnes (RSE 29%) in Hordaland, of which ∼40% (in weight) were landed in registered tourist fishing businesses, based on data from the tourist fishing survey. The results indicate that recreational anglers in Hordaland harvest more cod in coastal waters than commercial fishers. This study provides information for developing marine recreational fisheries monitoring in challenging survey situations to support science-based fisheries management.

What are the limitations for the use of Carbopack X as passive or active sampling adsorbent for determination of 1,3-butadiene in ambient environment?

Two widely used sampling methods for measurement of 1,3 butadiene in ambient air include active sampling and radial passive sampling techniques using sorbent tubes filled with Carbopack X adsorbent. The laboratory study was designed to evaluate the suitability of these sampling methods for long-term monitoring of 1,3-butadiene in ambient air. The results point against the use of passive radial diffusive sampling for determination of 1,3-butadiene due to the dependence of its uptake rate on experimental conditions. Inability to correctly reflect the occurrence of episodes of high concentration levels using radial diffusive passive sampling was proven experimentally. As for active sampling technique, caution must be taken as to not overreach the safe sampling limit which considerably decreases as a function of temperature and relative humidity. At 10 ml min −1 flow-rate, the breakthrough volume per gram of Carbopack X material is established at 81.6–84.0 L at 50% RH, 20 °C; 61.2–64.8 L at 80% RH, 20 °C; and 24.0–28.8 L at 80% RH, 30 °C. Relatively low sampling times associated with these sampling volumes point to the need to develop more adequate supports for active sampling to enable long-term ambient monitoring. • Limitations of current passive sampling techniques for measurement of 1,3-butadiene. • Limitations of current active sampling techniques for measurement of 1,3-butadiene. • Dependence of uptake rate of 1,3-butadiene using Radiello on environmental conditions. • Decrease of safe sampling limit as a function of environmental conditions.

Stem-nesting Hymenoptera in Irish farmland: empirical evaluation of artificial trap nests as tools for fundamental research and pollinator conservation

Insect pollinators are suffering global declines, necessitating the evaluation and development of methods for long-term monitoring and applied field research. Accordingly, this study evaluated the use of trap nests (“bee hotels”) as tools for investigating the ecology of cavity nesting Hymenoptera within Irish agricultural landscapes. Three trap nests consisting of 110 mm diameter plastic pipe containing 100 cardboard nest tubes of varying diameter were placed at eight apple orchards and eight oilseed rape sites and left in the field for five months. Sealed nest tubes occurred at 15 of the 16 sites, and in 77% of the 48 nests. However, only 7% of the 4800 individual nest tubes were sealed, and only 4% produced cavity-nesting Hymenoptera. Three cavity nesting bee species (Hylaeus communis, Osmia bicornis, Megachile versicolor) and two solitary wasp species (Ancistrocerus trifasciatus, A. parietinus) emerged from nest tubes. There were significant differences among species in terms of emergence date and the diameter of nest tubes from which they emerged, the latter allowing the calculation of niche width and niche overlap, and informing choice of tube size in future studies/conservation efforts. Trap nests, therefore, offer a valuable tool for fundamental ecological research and a model system for investigating interactions between stem-nesting species within their wider ecological networks. The ability of trap nests to actually increase farmland pollinator abundance and diversity as part of agri-environment schemes requires additional investigation. However, used in sufficient numbers, these trap nests provide valuable biogeographical data for cavity nesting Hymenoptera and offer a viable means for long term monitoring of these species in Irish farmland.

A Synthetic Aperture Radar Based Method for Long Term Monitoring of Seasonal Snowmelt and Wintertime Rain-On-Snow Events in Svalbard

Snow cover characteristics are highly sensitive to variations in temperature and precipitation. In Svalbard, these parameters are undergoing significant change in response to a rapidly warming climate and its associated positive feedback processes. The occurrence of wintertime rain-on-snow (ROS) events are expected to increase in frequency and intensity across the Arctic as a result of climate change. ROS events can dramatically alter snow cover characteristics, by saturating the snowpack and enhancing surface runoff as well as causing widespread formation of ground ice, which can negatively impact many ecosystems as well as infrastructure. Knowledge of the spatial and temporal variations in ROS occurrence across Svalbard, both past and present is needed to understand which areas are most vulnerable to ROS impacts and how this may change in the future. Until now comparatively few studies have exploited remote sensing methods to detect and monitor ROS occurrence and even these have been limited to relatively coarse spatial resolutions. This work has utilized C-band Synthetic Aperture Radar (SAR) observations to produce a 17-year dataset (2004–2020) of wet snow cover observations for Svalbard, from which a method for detecting and mapping both spring melt onset and ROS frequency has been developed. The mean spatial variations in melt onset and ROS occurrence reflect the geographical gradients in temperature and precipitation across the archipelago and are largely in agreement with current knowledge. The timing of ROS onset as detected using the SAR observations coincide well with in-situ measurements of rainfall, however in some cases the duration of a ROS event cannot be reliably estimated using SAR observations of wet snow, in particular after phase transitions from rain to snow. Linear trends derived from the limited time series of observations suggests that ROS frequency is increasing over most of the archipelago, but significant and large increases are confined to the south and west coast of the archipelago. However, low elevation areas in the central parts of the archipelago also exhibit a significant and decreasing trend in ROS occurrence over the time period studied.

Classification of Sleep-Wake State in Ballistocardiogram system based on Deep Learning.

Sleep state classification is essential for managing and comprehending sleep patterns, and it is usually the first step in identifying sleep disorders. Polysomnography (PSG), the gold standard, is intrusive and inconvenient for regular/long-term sleep monitoring. Many sleep-monitoring techniques have recently seen a resurgence as a result of the rise of neural networks and advanced computing. Ballistocardiography (BCG) is an example of such a technique, in which vitals are monitored in a contactless and unobtrusive manner by measuring the body's reaction to cardiac ejection forces. A Multi-Headed Deep Neural Network is proposed in this study to accurately classify sleep-wake state and predict sleep-wake time using BCG sensors. This method achieves a 95.5% sleep-wake classification score. Two studies were conducted in a controlled and uncontrolled environment to assess the accuracy of sleep-awake time prediction. Sleep-awake time prediction achieved an accuracy score of 94.16% in a controlled environment on 115 subjects and 94.90% in an uncontrolled environment on 350 subjects. The high accuracy and contactless nature make this proposed system a convenient method for long-term monitoring of sleep states, and it may also aid in identifying sleep stages and other sleep-related disorders. Clinical Relevance- Current sleep-wake state classification methods, such as actigraphy and polysomnography, necessitate patient contact and a high level of patient compliance. The proposed BCG method was found to be comparable to the gold standard PSG and most wearable actigraphy techniques, and also represents an effective method of contactless sleep monitoring. As a result, clinicians can use it to easily screen for sleep disorders such as dyssomnia and sleep apnea, even from the comfort of one's own home.

Magnetic resonance imaging of the heart as a method of long-term monitoring of right heart function after tetralogy of Fallot surgery

<p><strong>Introduction.</strong> Cardiac magnetic resonance imaging (CMR) is considered the reference diagnostic method for quantifying right ventricular size and function, and pulmonary regurgitation in patients with tetralogy of Fallot surgery. The aim of this paper is to confirm the importance of magnetic resonance continuous postoperative monitoring of right and left heart function parameters as a diagnostic method that provides the most precise and accurate assessment.</p><p><strong>Methods.</strong> The prospective observational study included subjects with TOF surgery who were diagnosed with residual morphological and/or functional disorders on control postoperative echocardiographic examinations. All subjects underwent magnetic resonance imaging of the heart on a 1.5 T scanner with dedicated coils for the heart surface according to the standard protocol for a period of one year from the beginning of the study. Criteria for exclusion from the study were: significant residual pulmonary stenosis, condition after pulmonary valve replacement, existence of residual shunt lesions, contraindications for cardiac magnetic resonance imaging (pacemaker, ICD, claustrophobia). Depending on the time elapsed since the tetralogy of Fallot surgery, the subjects were divided into groups: more than 15 years, 11−15 years, 6−10 years, less than 5 years.</p><p><strong>Results.</strong> The study included 131 subjects with an average age of 24.18 ± 11.57 years with complete correction of TOF. Intergroup differences in values of right ventricular enddiastolic volume, right ventricular ejection fraction, and left ventricular ejection fraction were demonstrated, but there was no statistically significant intergroup difference in values of pulmonary regurgitation fraction. The negative interaction of the right and left ventricles intensifies during the years of follow-up of patients after TOF surgery, which is especially true fifteen years after surgery.</p><p><strong>Conclusion.</strong> CMR has the most significant role in research efforts aimed at improving the outcomes of operated patients with tetralogy of Fallot.</p>

SEALNET: Facial recognition software for ecological studies of harbor seals.

Methods for long‐term monitoring of coastal species such as harbor seals (Phoca vitulina) are often costly, time‐consuming, and highly invasive, underscoring the need for improved techniques for data collection and analysis. Here, we propose the use of automated facial recognition technology for identification of individual seals and demonstrate its utility in ecological and population studies. We created a software package, SealNet, that automates photo identification of seals, using a graphical user interface (GUI) software to detect, align, and chip seal faces from photographs and a deep convolutional neural network (CNN) suitable for small datasets (e.g., 100 seals with five photos per seal) to classify individual seals. We piloted the SealNet technology with a population of harbor seals located within Casco Bay on the coast of Maine, USA. Across two years of sampling, 2019 and 2020, at seven haul‐out sites in Middle Bay, we obtained a dataset optimized for the development and testing of SealNet. We processed 1752 images representing 408 individual seals and achieved 88% Rank‐1 and 96% Rank‐5 accuracy in closed set seal identification. In identifying individual seals, SealNet software outperformed a similar face recognition method, PrimNet, developed for primates but retrained on seals. The ease and wealth of image data that can be processed using SealNet software contributes a vital tool for ecological and behavioral studies of marine mammals in the developing field of conservation technology.

Sampling method for long-term monitoring of indoor environmental quality in residential buildings

The data collected during long-term monitoring (LTM) of indoor environmental quality (IEQ) can reflect occupants’ exposure to contaminants and can be used to improve thermal comfort. As there are large differences among existing guidelines for IEQ monitoring of dwellings, it is important to identify a sampling method that balances data accuracy, sample size and cost. This paper reports the major findings that developed a systematic approach to determining the sample method for IEQ monitoring. In the study, LTM was carried out in 13 naturally ventilated urban residences in Kunming, China. We proposed the continuous sampling strategy (CSS) and discrete sampling strategy (DSS). Descriptive statistics was used to evaluate the performances of both strategies, and it was found that DSS could obtain more accurate data than CSS. Next, an algorithm was developed for calculating the optimal sampling frequencies for different parameters based on the Pearson correlation coefficient. We evaluated the required number of dwellings(RND) for various parameters that satisfied the statistical confidence in Kunming and other four cities of China. We found that with the increase in the household number in one city, the RND will reach to a critical threshold and no longer increase anymore. Using this threshold and the simple random sampling principle, we also provide guidance for determining the RND for IEQ monitoring in residence. It is expected that the results of this study will facilitate the selection of sampling method for similar studies in the future, with reduced manpower and consumption but a representative sample.

Monitoring natural gas storage using Synthetic Aperture Radar: are the residuals informative?

SUMMARY Estimates of line-of-sight (LOS) displacements from Interferometric Synthetic Aperture Radar (InSAR) observations serve as the basis of the long-term monitoring of an operating natural gas storage site at Honor Rancho in California. An inversion algorithm is used to estimate the portion of the signal that is attributable to deformation within the gas storage reservoir, located at a depth of around 3 km. Removing this contribution produces residuals that are used to characterize the background variation is surface deformation at the gas storage facility and to determine a threshold that can signify unusually large residuals. An application to almost 7 yr of InSAR data, from 2011 until 2018, indicates that there are intervals of heightened residuals as well as brief episodes of anomalously large misfits. An examination of the spatial distributions of the individual residual LOS displacements indicates larger displacements in an alluvial valley just south of the reservoir, with rapid spatial variations in sign, indicating a rather shallow origin. Furthermore, the two anomalous events also involve rapid spatial variations in the LOS displacement residuals directly above the storage facility. The results demonstrate that the technique of extracting residuals after removing the reservoir signal is a useful approach, even in the case of this deep reservoir, and is a promising method for long-term monitoring.

A monitoring method for car-body vibration displacement of a high-speed train in windy conditions

The long-term monitoring of car-body vibration displacement when a high-speed train passes through complex terrain sections in windy conditions has become an urgent engineering problem in China. However, few studies have focused on this topic, and an effective engineering long-term monitoring method is lacking in China. In this study, by combining the vibration characteristics and structural characteristics of railway vehicles, a real-time car-body displacement monitoring method to fulfill monitoring requirements was proposed, and a mathematical computational model based on space coordinate transformations to calculate the car-body displacements in operation was developed. Moreover, the comparison and the verification of the monitoring system accuracy were conducted using full-scale tests. The results showed that the displacement of the car-body relative to the bogie frame obtained through the system was consistent with the real vibration state of the car-body. Therefore, our monitoring system was reliable in reflecting the car-body vibration displacement changes in high-speed trains that were in motion.

The culprit of cryptogenic stroke: the short-term versus long-term atrial fibrillation detection rate in a tertiary care centre

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Limburg Clinical Research Center OnBehalf Mobile Health Unit & Future Health Background Cryptogenic stroke (CS) and transient ischemic attack (TIA) patients have no determined aetiology at discharge. A possible cause for stroke is atrial fibrillation (AF). AF occurs in 20%-40% of the CS patients and diagnosis is highly dependent on monitoring duration. A long-term monitoring method is the insertable loop recorder (ILR), recommended by the European Society of Cardiology. However, this is not routinely used in Belgium despite reimbursement. Purpose This study aims to determine the AF detection rates of different methods used in clinical practice, ranging from short-term monitoring (monitoring in a stroke unit, 12-lead electrocardiogram (ECG), and 24-hour ECG), seven-day Holter, and long-term monitoring (smartphone application and ILR). Methods A monocentric, retrospective study was conducted in adults with CS or TIA between 1/01/17 - 1/01/20. Data were collected from the electronic medical record. The primary endpoint was the detection rate and time until first AF detection. Results A total of 368 patients suffered from a CS or TIA. Most of them were monitored in the stroke unit (96%) or with a 12-lead ECG (93%). A 24-hour ECG was used in 26%, a seven-day Holter in 38%. For long-term monitoring, a smartphone application was used in 3%. ILRs were inserted in 6%, with a median time of 102 days after stroke (IQR: 48-321). One year after ILR insertion, AF was detected in 23%. AF detection increased with monitoring duration, as shown in the figure, except for 24-hour ECG, which detected no AF. Therefore, the AF detection rate was different between short-term monitoring (5%)  and seven-day Holter (10%; p=.034), and short- and long-term monitoring (16%; p=.01). The age of CS patients without AF (Mdn = 71yr) was lower than those with AF (Mdn = 79yr; p=.001). The National Institutes of Health Stroke Scale (NIHSS) and the CHA2DS2-VASc score of patients without AF (Mdn = 3) was lower than those with AF (Mdn = 6, p<.001; Mdn = 4, p=.004 respectively). The one-year mortality of patients with AF was 15% compared to 8% for patients without AF. No patients with an ILR deceased within one year after the stroke. Conclusions Detection of AF was associated with higher age, NIHSS, and CHA2DS2-VASc scores. These variables can be used to select patients for the insertion of ILRs. The detection rate of AF was significantly higher with long-term monitoring and seven-day Holter compared to short-term monitoring. However, only 38% of the patients were monitored for a week, and only 6% had an ILR inserted. Therefore, despite guideline recommendations, long-term cardiac monitoring is underutilised in this population of CS patients. Nevertheless, AF was still detected in 14% of CS patients within one year after the stroke. These findings emphasise the need for more monitoring with a seven-day Holter, smartphone app, and ILR in this patient population. Consequently, this will result in more accurate treatment of AF as secondary prevention of CS. Abstract Figure. Time to first AF detection after stroke

A geoelectrical pre-study of Älvkarleby test embankment dam: 3D forward modelling and effects of structural constraints on the 3D inversion model of zoned embankment dams

Electrical resistivity tomography has potential as a complementary long-term monitoring method in embankment dams; however, the 3D character of the geometry including the shape of the embankment, its internal zoned construction and the reservoir water make interpretation challenging. To tackle this problem, a qualified inversion model considering the 3D environment is necessary. In this paper, prior information about the resistivity of different parts of a test embankment dam was used as constraints in order to increase the capability of defect detection in a complex 3D context. Five small defects were incorporated into the core of the model. Laboratory measurements were made on samples of the materials intended to be used for the construction of a test embankment dam, and resistivity values provided from the laboratory measurements were used in the forward modelling. A measurement sequence of around 8000 synthetic data points using extended gradient, crossline bipole-bipole and corner arrays between horizontal-horizontal, vertical-vertical, and vertical-horizontal lines were modelled and inverted all at once. The structural constraints were applied to increase the accuracy of inversion, using the L1 and L2 methods. Different mesh qualities with different boundaries for each region and 3D geometric factor calculation were applied for the inversion to evaluate the effects of region control incorporated in the inversion process. The results showed that L1 and L2 norm inversions combined with region control can determine the location of very small defects and finding the defects located near each other, respectively. Removing the region control from the inversion caused unrealistic resistivity prediction for some regions and the inability to discover the dam defects. Therefore, the proposed methodology can decrease non-uniqueness in the inversion and make time-lapse ERT a valuable monitoring tool that complements other instrumentation techniques and based on these results it was concluded promising to continue with the construction of the test dam using the same type of defects and electrode set-up, for verification under field-conditions.

Evaluation of counting methods for monitoring populations of a cryptic alpine passerine, the rock wren (Passeriformes, Acanthisittidae, Xenicus gilviventris).

Developing and validating methods to determine trends in populations of threatened species is essential for evaluating the effectiveness of conservation interventions. For cryptic species inhabiting remote environments, this can be particularly challenging. Rock wrens, Xenicus gilviventris, are small passerines endemic to the alpine zone of southern New Zealand. They are highly vulnerable to predation by introduced mammalian predators. Establishing a robust, cost-effective monitoring tool to evaluate population trends in rock wrens is a priority for conservation of both the species and, more broadly, as part of a suite of indicators for evaluating effectiveness of management in New Zealand's alpine ecosystems. We assessed the relative accuracy and precision of three population estimation techniques (mark-resight, distance sampling and simple counts on line transects) for two populations of rock wrens in the Southern Alps over six breeding seasons (2012-2018). The performance of these population estimators was compared to known rock wren population size derived from simultaneous territory mapping. Indices of abundance derived from counts on transects were correlated with territory mapping at both study areas, and performed better than either mark-resight methods or distance sampling. Simple counts on standardised line transects are a highly cost-effective method of monitoring birds because they do not require banding a population. As such, we recommend that line transect counts using the design outlined in this paper be adopted as a standard method for long-term monitoring of rock wren populations. Although species-specific testing is required to validate use of low-cost population indices, our results may have utility for the monitoring of other cryptic passerines in relatively open habitats.