Spatial Concordance Research Articles

Sequence comparison of spoiled gradient echo and balanced steady-state free precession for pulmonary free-breathing proton MRI in patients and healthy volunteers: Correspondence, repeatability, and validation with dynamic contrast-enhanced MRI.

Phase-resolved functional lung (PREFUL) MRI is a proton-based, contrast agent-free technique derived from the Fourier decomposition approach to measure regional ventilation and perfusion dynamics during free-breathing. Besides the necessity of extensive PREFUL postprocessing, the utilized MRI sequence must fulfill specific requirements. This study investigates the impact of sequence selection on PREFUL-MRI-derived functional parameters by comparing the standard spoiled gradient echo (SPGRE) sequence with a lung-optimized balanced steady-state free precession (bSSFP) sequence, thereby facilitating PREFULs clinical application in pulmonary disease assessment. This study comprised a prospective dataset of healthy volunteers and a retrospective dataset of patients with suspected chronic thromboembolic pulmonary hypertension. Both cohorts underwent PREFUL-MRI with both sequences to assess the correspondence of PREFUL ventilation and perfusion parameters (A). Additionally, healthy subjects were scanned a second time to evaluate repeatability (B), whereas patients received dynamic contrast-enhanced (DCE)-MRI, considered the perfusion gold standard for comparison with PREFUL-MRI (C). Signal-to-noise ratio (SNR), calculated from the unprocessed images, was compared alongside median differences of PREFUL-MRI-derived parameters using a paired Wilcoxon signed rank test. Further evaluations included calculation of the Pearson correlation, intraclass-correlation coefficient for repeatability assessment, and spatial overlap (SO) for regional comparison of PREFUL-MRI and DCE-MRI. bSSFP showed a clear SNR advantage over SPGRE (median: 23 vs. 9, p< 0.001). (A) Despite significant differences, parameter values were strongly correlated (r≥0.75). After thresholding, binary maps showed high healthy overlap across both cohorts (SOHealthy > 86%) and high defect overlap in the patient cohort (SODefect≥48%). (B) bSSFP demonstrated slightly higher repeatability across most parameters. (C) Both sequences demonstrated comparable correspondence to DCE-MRI, with SPGRE excelling in absolute quantification and bSSFP in spatial agreement. Although bSSFP showed superior SNR results, both sequences displayed spatial defect concordance and highly correlated PREFUL parameters with deviations regarding repeatability and alignment with DCE-MRI.

Mapping interictal discharges using intracranial EEG-fMRI to predict postsurgical outcomes.

Various subjective and objective methods have been proposed to identify which interictal epileptiform discharge (IED)-related EEG-fMRI results are more likely to delineate seizure generating tissue in patients with drug-resistant focal epilepsy for the purposes of surgical planning. In this intracranial EEG-fMRI study, we evaluated the utility of these methods to localize clinically relevant regions pre-operatively and compared the extent of resection of these areas to post-operative outcome. Seventy patients admitted for intracranial video-EEG monitoring were recruited for a simultaneous intracranial EEG-fMRI study. For all analyses of blood oxygen level-dependent responses associated with IEDs, an experienced epileptologist identified the most Clinically Relevant brain activation cluster using available clinical information. The Maximum cluster (the cluster with the highest z-score) was also identified for all analyses and assigned to one of three confidence levels (low, medium, or high) based on the difference of the peak z-scores between the Maximum and Second Maximum cluster (the cluster with the second highest peak z-value). The distance was measured and compared between the peak voxel of the aforementioned clusters and the electrode contacts where the interictal discharge and seizure onset were recorded. In patients who subsequently underwent epilepsy surgery, the spatial concordance between the aforementioned clusters and the area of resection was determined and compared to post-operative outcome. We evaluated 106 different IEDs in 70 patients. Both subjective (identification of the Clinically Relevant cluster) and objective (Maximum cluster much more significant than the second maximum cluster) methods of culling non-localizing EEG-fMRI activation maps increased the spatial concordance between these clusters and the corresponding IED or seizure onset zone contacts. However, only the objective methods of identifying medium and high confidence maps resulted in a significant association between resection of the peak voxel of the Maximum cluster and post-operative outcome. Resection of this area was associated with good post-operative outcomes but was not sufficient for seizure freedom. On the other hand, we found that failure to resect the medium and high confidence Maximum clusters was associated with a poor post-surgical outcome (negative predictive value = 1.0, sensitivity = 1.0). Objective methods to identify higher confidence EEG-fMRI results are needed to localize areas necessary for good post-operative outcomes. However, resection of the peak voxel within higher confidence Maximum clusters is not sufficient for good outcomes. Conversely, failure to resect the peak voxel in these clusters is associated with a poor post-surgical outcome.

A Dorsal Skinfold Window Chamber Tumor Mouse Model for Combined Intravital Microscopy and Magnetic Resonance Imaging in Translational Cancer Research.

Preclinical intravital imaging such as microscopy and optical coherence tomography have proven to be valuable tools in cancer research for visualizing the tumor microenvironment and its response to therapy. These imaging modalities have micron-scale resolution but have limited use in the clinic due to their shallow penetration depth into tissue. More clinically applicable imaging modalities such as CT, MRI, and PET have much greater penetration depth but have comparatively lower spatial resolution (mm scale). To translate preclinical intravital imaging findings into the clinic, new methods must be developed to bridge this micro-to-macro resolution gap. Here we describe a dorsal skinfold window chamber tumor mouse model designed to enable preclinical intravital and clinically applicable (CT and MR) imaging in the same animal, and the image analysis platform that links these two disparate visualization methods. Importantly, the described window chamber approach enables the different imaging modalities to be co-registered in 3D using fiducial markers on the window chamber for direct spatial concordance. This model can be used for validation of existing clinical imaging methods, as well as for the development of new ones through direct correlation with "ground truth" high-resolution intravital findings. Finally, the tumor response to various treatments-chemotherapy, radiotherapy, photodynamic therapy-can be monitored longitudinally with this methodology using preclinical and clinically applicable imaging modalities. The dorsal skinfold window chamber tumor mouse model and imaging platforms described here can thus be used in a variety of cancer research studies, for example, in translating preclinical intravital microscopy findings to more clinically applicable imaging modalities such as CT or MRI.

Matching the elemental fingerprints of fish otoliths with water masses of the St. Lawrence River and its tributaries, Canada

The physicochemical heterogeneity of large river ecosystems generates a mosaic of habitats that support diverse fish communities. Understanding the connectivity between habitats and exploited fish populations is necessary for the sustainable management of fisheries. This study evaluates the spatial concordance between elemental fingerprints of fish otoliths and surface waters in the St. Lawrence River (Canada) and its tributaries. We sampled 16 tributaries and various freshwater habitats of the St. Lawrence River and collected 136 water samples and 930 fish, representing 21 species. We observed a high spatial variability of trace element composition in the water and fish otolith samples. Reclassification using Sr and Ba concentrations of the collected water and otoliths was sufficiently accurate to correctly assign most fish to their capture region. We also observed significant variation in the elemental deposition relationships for Sr and Ba among fish families. The development of this elemental fingerprint reference database is fundamental for understanding the structure of exploited fish populations, validating the connectivity among habitats, and reconstructing habitat use by invasive fish species.

Abstract 1041: Spatial concordance between genome and proteome in oncology: A systematic review

Abstract We recently reported that spatial transcriptome data can be used to spatially detect copy number alterations (Erickson et al., Nature, 2022). Given that copy-number alterations may also be reflected by altered protein expression in human cancers, we sought to determine what the empirical concordance of the spatial proteome and genome in human cancer samples. We performed a systematic review of Immunohistochemistry (IHC) &amp; Fluorescence/Chromogenic In-Situ Hybridization (FISH/CISH) across human cancers. We performed a PUBMED query for records up to April 1st, 2023, yielding 9,294 records. Our inclusion criteria included human sample studies that performed both IHC and FISH/CISH against the same target, with a minimum of two samples. We excluded case reports, RNA ISH- and non-human studies, studies without IHC/ISH performed on the same target, and articles not in English or inaccessible. We screened 9,294 PUBMED article abstracts using the AS Review active learning model (van de Schoot et al., 2021), and used a pre-defined threshold of 5 % consecutive irrelevant abstracts to stop screening. A total of 1,309 abstracts were manually excluded using the AS Review, directing the active learning model to automatically exclude 3,413 abstracts out of the original 9,294. Of the 4,572 articles assessed for full-article screening, 1,167 were excluded for being out of scope, 303 for access issues, 227 for language incompatibility, and 236 for imprecise information, primarily due to non-representative samples or incorrect gene/protein target identification. Ultimately, out of 2,413 articles assessed for eligibility, 2,294 did not meet inclusion criteria, leaving 119 studies for our analysis. From these articles, we manually extracted kappa values for analysis and visualization in R. We identified articles from 19 different cancers with the majority studying Breast Cancer, Non-Small Cell Lung Cancer, Gastric Cancer, and Mesothelioma. We observed high Cohen’s Kappa values in Breast Cancer (median = 0.76), Non-Small Cell Lung Cancer (median = 0.91) and Mucinous Ovarian Carcinoma (median = 0.93). We identified studies from 14 different genes with majority being HER2, ALK and MYC. We observed high Cohen’s Kappa values in HER2 (median = 0.80), ALK (median = 0.80), ROS1 (median = 0.95) and MDM2 (median = 0.72). Our preliminary analysis indicates significant heterogeneity between tumor types for protein expression and copy-number alterations. To our knowledge, there are no previously reported systematic reviews that have empirically assessed the spatial concordance of proteome and genome, in human cancer samples. The authors often reported IHC/FISH results at patient, or section level, potentially introducing selection bias by not accounting for intra-tumoral heterogeneity at single-cell resolution. Future efforts are needed to spatially resolve gene-copy number and protein expression at single-cell resolution. Citation Format: Laura K. Sysivirta, Franziska Niemeyer, Veera Kurki, Inkalilja Pirinen, Laura Savolainen, Ceren Seref-Vujaklilja, Andrew Erickson. Spatial concordance between genome and proteome in oncology: A systematic review [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1041.

Frequency characteristics of temporal and spatial concordance among dynamic indices in inattentive and combined subtypes of attention deficit hyperactivity disorder.

Numerous voxel-based resting-state functional magnetic resonance imaging (rs-fMRI) measurements have been used to characterize spontaneous brain activity in attention deficit hyperactivity disorder (ADHD). However, the practical distinctions and commonalities among these intrinsic brain activity measures remain to be fully explored, and whether the functional concordance is related to frequency is still unknown. The study included 25 ADHD, combined type (ADHD-C); 26 ADHD, inattentive type (ADHD-I); and 28 typically developing (TD) children. We calculated the voxel-wise (temporal) and volume-wise (spatial) concordance among dynamic rs-fMRI indices in the slow-5 (0.01-0.027 Hz) and slow-4 (0.027-0.073 Hz) frequency bands, respectively. The spatiotemporal concordance within the slow-4 and slow-5 bands among the ADHD-C, ADHD-I, and TD groups was compared. Although the ADHD-C and ADHD-I groups showed similar volume-wise concordance, comparison analysis revealed that compared with ADHD-C patients, ADHD-I patients exhibited decreased voxel-wise concordance in the right median cingulate and paracingulate gyrus (MCC) and right supplementary motor area (SMA) in the slow-5 band. In addition, the voxel-wise concordance was negatively correlated with the diagnostic scores of ADHD subtypes. Our results suggest that functional concordance is frequency dependent, and dynamic concordance analysis based on specific frequency bands may provide a novel approach for investigating the pathophysiological differences among ADHD subtypes.

Spatial correlation of left atrial low voltage substrate in sinus rhythm versus atrial fibrillation: The rhythm specificity of atrial low voltage substrate.

Improved sinus rhythm (SR) maintenance rates have been achieved in patients with persistent atrial fibrillation (AF) undergoing pulmonary vein isolation plus additional ablation of low voltage substrate (LVS) during SR. However, voltage mapping during SR may be hindered in persistent and long-persistent AF patients by immediate AF recurrence after electrical cardioversion. We assess correlations between LVS extent and location during SR and AF, aiming to identify regional voltage thresholds for rhythm-independent delineation/detection of LVS areas. (1) Identification of voltage dissimilarities between mapping in SR and AF. (2) Identification of regional voltage thresholds that improve cross-rhythm substrate detection. (3) Comparison of LVS between SR and native versus induced AF. Forty-one ablation-naive persistent AF patients underwent high-definition (1 mm electrodes; >1200 left atrial (LA) mapping sites per rhythm) voltage mapping in SR and AF. Global and regional voltage thresholds in AF were identified which best match LVS < 0.5 mV and <1.0 mV in SR. Additionally, the correlation between SR-LVS with induced versus native AF-LVS was assessed. Substantial voltage differences (median: 0.52, interquartile range: 0.33-0.69, maximum: 1.19 mV) with a predominance of the posterior/inferior LA wall exist between the rhythms. An AF threshold of 0.34 mV for the entire left atrium provides an accuracy, sensitivity and specificity of 69%, 67%, and 69% to identify SR-LVS < 0.5 mV, respectively. Lower thresholds for the posterior wall (0.27 mV) and inferior wall (0.3 mV) result in higher spatial concordance to SR-LVS (4% and 7% increase). Concordance with SR-LVS was higher for induced AF compared to native AF (area under the curve[AUC]: 0.80 vs. 0.73). AF-LVS < 0.5 mV corresponds to SR-LVS < 0.97 mV (AUC: 0.73). Although the proposed region-specific voltage thresholds during AF improve the consistency of LVS identification as determined during SR, the concordance in LVS between SR and AF remains moderate, with larger LVS detection during AF. Voltage-based substrate ablation should preferentially be performed during SR to limit the amount of ablated atrial myocardium.

Early‐phases [18F]florbetapir and [18F]flutemetamol images as proxies of brain metabolism in the Alzheimer’s disease spectrum

AbstractBackgroundAlzheimer’s disease (AD) neuropathologic changes are β‐amyloid (Aβ) deposition, pathologic tau, and neurodegeneration. Dual‐phase amyloid‐PET might be able to evaluate Aβ deposition and neurodegeneration with a single tracer injection. Early‐frames of amyloid‐PET scans provide a proxy for cerebral perfusion, which has shown good correlations with neural dysfunction measured through metabolic consumption, while the late‐frames depict amyloid distribution. Our study aims to assess the comparability between early frames of amyloid‐PET scans and [18F]fluorodeoxyglucose (FDG) PET in their topography and their ability to discriminate patients in the AD continuum.Method166 subjects evaluated at the Geneva Memory Center (Cognitively Unimpaired, CU = 61; Mild Cognitive Impairment, MCI = 73; Dementia = 21) underwent early‐phase amyloid‐PET – using either [18F]florbetapir (eFBP) (n = 95) or [18F]flutemetamol (eFMM) (n = 72) – and FDG PET. Standardized uptake value ratios (SUVR) were extracted within key regions sensitive for AD (metaROI) to evaluate the correlation of eFBP/eFMM and their respective FDG PET scans. To compare the discriminative power of eFBP, eFMM, and FDG SUVR between Aβ‐negative CU and Aβ‐positive impaired patients, receiver operating characteristic analyses and voxel‐wise t‐tests were performed. SPM single‐subject procedure was applied to investigate hypometabolic and hypoperfusion maps and their spatial overlap by means of DICE.ResultStrong positive correlations were found between eFBP/eFMM and FDG SUVR independently of Aβ status and Aβ radiotracers (r&gt;0.85, p&lt;0.001). Both eFBP and eFMM, and FDG SUVR significantly discriminated AD cognitively impaired patients from CU in the metaROI (AUCFBP = 0.768; AUCFMM = 0.778), with FDG performing slightly better than others (AUCFDG = 0.797). For all tracers, voxel‐wise analyses confirmed reduced signals in regions typically belonging to AD hypometabolic pattern in AD patients when compared to controls. SPM single‐subject analysis revealed different hypometabolism and hypoperfusion patterns with a high spatial concordance, differing between stages (DICE average: AD dementia = 0.91; Aβ‐positive MCI = 0.61).ConclusionDistribution of perfusion was comparable to that of metabolism at group level and at single‐subject level. Our findings indicate that eFBP and eFMM imaging provide information closely related to brain regional glucose metabolism supporting their use for individual classification in clinical practice.

Concordance between focal brain temperature elevations and focal edema in temporal lobe epilepsy.

Neuroinflammation (NI) is a pathophysiological factor in many neurological disorders, including epilepsy. Because NI causes microstructural tissue damage that worsens with increasing brain temperature, abnormally elevated brain temperatures may be a surrogate measure of the biochemical consequences of NI. This study investigated whether patients with temporal lobe epilepsy (TLE) have abnormal brain temperature elevations (TCRE ) in seizure-producing regions that show evidence of edema and/or microstructural damage. Twenty adults with TLE and 20 healthy controls (HCs) were scanned at 3-Tesla. TCRE in each voxel was calculated (TCRE =-102.61(ΔH20-CRE) + 206.1°C) by non-invasive volumetric magnetic resonance spectroscopic imaging and thermometry (MRSI-t). Multi-shell diffusion images were processed by neurite orientation and density imaging (NODDI). Voxel wise two-sample t tests computed group differences in imaging data. Multimodal data fusion (joint independent component analysis [ICA]) determined the spatial coupling of TCRE with NODDI. TCRE analyses showed that, compared to HCs, TLEs had higher TCRE (p < .001). NODDI analyses showed increased extracellular free water (pFWE < 0.05) in the medial temporal lobes, with the most pronounced increases ipsilateral to seizure onset. TLEs also had increased angular dispersion of neurites (p < .001) and decreased neurite density (pFWE <0.05) in the ictal-onset medial temporal lobe, as well as more widespread, bilateral patterns of abnormalities. Focal increases in TCRE were spatially concordant with increased free water in the left inferior and middle temporal gyri and the associated cortex. In TLE, ICA loadings extracted from this region of overlap were associated with greater mood disturbance (r=.34, p=.02) and higher depression scores (r=.37, p=.009). The spatial concordance between focal TCRE elevations and edema in TLE supports the notion that brain thermometry visualizes the correlates of focal NI. MRSI-t-based TCRE elevations may, therefore, be a useful biomarker for identifying seizure-producing tissue in patients with focal epilepsy caused by brain damage.

Interpersonal coordination in schizophrenia: a concise update on paradigms, computations, and neuroimaging findings.

Abstract Social functioning impairment is a hallmark of mental illness. As one of the most intractable and severe psychiatric disorders, schizophrenia is characterized by deficits on multiple social cognitive domains. In particular, failures of interpersonal coordination (i.e., actions that occur in spatial and temporal concordance with those of other individuals in a social setting) in schizophrenia are closely linked to significant prognostic indicators, such as symptom remission, quality of life, and employment. Despite the increasing interest in the psychological and neural mechanisms of interpersonal coordination in schizophrenia, important gaps in our understanding remain. Notably, the study of the mechanisms underpinning interpersonal coordination is currently undergoing a methodological shift, moving its focus from single-person tasks to second- and multi-person paradigms, and from model-free to model-based analyses. However, applications of these advanced approaches in schizophrenia has been slow. Here, we provide a concise update on the uses of multi-person paradigms to study interpersonal coordination and mathematical models to dissect its computational mechanisms, at both behavioral and neural levels. We then review prior studies on large-scale neuroimaging studies that explore brain correlates of general social functions and further pointed to the implementation of dissecting interpersonal coordination deficits in schizophrenia. Finally, we highlight key challenges as well as exciting opportunities for integrating research in computational psychiatry with second- and multi-person approaches in investigating interpersonal coordination deficits in schizophrenia.

Diversity of eukaryotic and prokaryotic microbiota revealed by metabarcoding in Neotropical floodplain lakes.

The diversity of eukaryotic and prokaryotic communities has been assessed by morphological and genetic approaches, which are used to characterize the microbiota in different environments. Here, planktonic prokaryotic and eukaryotic communities of the Araguaia River, located in the Central region of Brazil, were analyzed based on metabarcoding analysis of rRNA genes to evaluate the diversity of these groups in tropical floodplain lakes. Also, we tested their spatial concordance throughout the Araguaia river. Water samples were collected from 8 floodplain lakes in Araguaia River. The 16S and 18S rRNA genes were amplified and sequenced using Illumina MiSeq. For eukaryotes, 34,242 merged reads were obtained and 225 distinct OTUs were delineated, of which 106 OTUs were taxonomically classified. For prokaryotes, 26,426 sequences were obtained and 351 OTUs were detected. Of them, 231 were classified in at least one taxonomic category. The most representative eukaryotes belonged to Ciliophora, Chlorophyta and Charophyta. The prokaryotic phylum with the most OTUs classified were Proteobacteria, Actinobacteria and Bacteroidetes. The lakes did not show spatial concordance when comparing the similarity between their microbiota. The knowledge of freshwater biodiversity using DNA sequencing for important rivers, such as Araguaia River, can improve microbiota inventories of tropical biodiversity hotspots.

Homogenisation of water and sediment bacterial communities in a shallow lake (lake Balihe, China)

Abstract Planktonic and benthic bacterial communities hold central roles in the functioning of freshwater ecosystems and mediate key ecosystem services such as primary production and nutrient remineralisation. Although it is clear that such communities vary in composition both within and between lakes, the environmental factors and processes shaping the diversity and composition of freshwater bacteria are still not fully understood. In order to assess seasonal and spatial variability in lake bacterial communities and identify environmental factors underpinning biogeographical patterns, we performed a large‐scale sampling campaign with paired water and sediment sample collection at 18 locations during four seasons in Lake Balihe, a subtropical shallow fish‐farming lake in mid‐eastern China. Pelagic and benthic bacterial communities were distinctly different in terms of diversity, taxonomic composition and community structure, with Actinobacteria, Bacteroidetes, Cyanobacteria and Alphaproteobacteria dominating lake water, and Acidobacteria, Bacteroidetes, Chloroflexi, Gammaproteobacteria and Deltaproteobacteria dominating sediment. Nevertheless, these two communities had stronger spatial concordance and overlap in taxa during spring and autumn seasons. Together, the main drivers of both the spatial and temporal variations in Lake Balihe bacterial communities were identified as water temperature, turbidity, nitrogen and phosphorus availability, and thermal stratification controlled by wind‐mixing and activity of the dense farmed fish populations. Notably, populations affiliated with Firmicutes, known to be abundant in fish gut microbiome, were especially abundant in the summer season and locations where high fish biomass was found, suggesting a potential link between fish gut microbiome and the pelagic bacterial communities. Our findings demonstrated seasonal homogenisation of pelagic and benthic bacterial communities linked to marked shifts in a set of seasonally‐driven environmental variables including water temperature and nutrient availability.

Abstract 13156: The Location of Combined High-Risk Low Endothelial Shear Stress and High Plaque Structural Stress is Distant From the Minimal Lumen Area in the Majority of Coronary Plaques Responsible for Major Adverse Cardiac Events

Introduction: The presence of multiple high-risk prognostic features enhances risk-stratification of plaques prone to destabilization and major adverse cardiac events (MACE). Spatial superimposition of high-risk features (concordance) likely amplifies local risk. Local endothelial shear stress (ESS) and plaque structural stress (PSS) metrics predict MACE, but their spatial concordance and their location relative to the minimal lumen area (MLA) is unknown. If the highest-risk plaque area is distant from the MLA, then PCI of the MLA alone will leave high-risk plaque areas untreated. Purpose: To identify the site of high-risk features of low ESS and high PSS heterogeneity (HI) along the course of a plaque in patients who develop MACE, and the site of their spatial concordance relative to the MLA. Methods: We examined ESS, PSS, and PSS HI in 22 non-culprit lesions (NCL) leading to MACE, and 64 randomly selected control NCLs without MACE from the PROSPECT study. ESS was calculated by computational fluid dynamics and PSS by finite element analysis on co-registered lesions. We examined high-risk plaques with empirically-derived (ROC curve) ESS &lt; 1.3 Pa and PSS HI &gt; 0.29 in 16 lesions leading to future MACE, and 11 control lesions without MACE. Results: MACE outcomes were significantly more frequent in plaques with combined low ESS+high PSS HI vs plaques with low ESS alone (72.7% vs 27.3%, p&lt;0.001) at 3 years follow-up. Of the 16 MACE plaques with both low ESS+high PSS HI, 14 exhibited high-risk values that were spatially concordant vs 2 that were discordant (87.5% v 12.5%, p=0.01). In the 14 plaques with concordant values, there were 26 focal plaque areas with high-risk concordance. The mean distance from the concordant high-risk areas to the MLA was 13.2 ± 11.6 mm (Figure). Conclusion: High-risk ESS and PSS measures frequently co-localize in plaques responsible for future MACE, and are substantially distant from the MLA. PCI of the MLA area alone may leave many high-risk areas untreated.

Brazilian marine phylogeography: A literature synthesis and analysis of barriers.

In the last 30 years a plethora of phylogeography studies have been published targeting Brazilian marine species. To date, several historical and extant physical and ecological processes have been identified as drivers of allopatric, sympatric and parapatric population genetic differentiation detected along the Brazilian coast. Examples of extant physical barriers include the split of the South Equatorial Current into the Brazil and North Brazil boundary currents, the mouth of major rivers (e.g., Amazon, São Francisco and Doce rivers) and coastal upwellings. Examples of historical barriers include the Vitória-Trindade seamount chain promoting genetic differentiation during periods of glacial maxima and lower sea levels. Examples of ecological speciation include adaptations to different substrata, resource use and reproductive biology. We used published data to build data sets and generalized additive models to identify patterns of spatial phylogeographical concordance across multiple taxa and markers. Our results identify Cape São Roque as the most dominant extant barrier to gene flow along the Brazilian coast, followed by the Vitória-Trindade seamount chain and Cape Santa Marta. Cape Santa Marta is the northern winter limit of the Rio da Plata plume and is intermittently influenced by the Malvinas Current. This study provides a novel explicit quantitative approach to comparative phylogeography that recognizes four Brazilian phylogeographical regions delimited by processes associated with barriers to gene flow.

Multi-criteria framework for identifying the trade-offs and synergies relationship of ecosystem services based on ecosystem services bundles

The interaction relationship of ecosystem services (ESs) is among the most critical objective in natural resource management. However, a complexity of the spatial heterogeneity of delivering multiple ESs from social-ecological system was seldomly considered. To enhance the linkage between the spatial concordance and interaction relationship of ESs, we presented a multi-criteria framework for identifying the trade-offs and synergies relationship of ESs. The conceptual steps were to i) divide the ES groups based on different ES bundles, ii) select appropriate methods for each ES bundle based on the number of dominant ESs and iii) determine the trade-offs and synergies relationship of pair-wise ESs among ES bundles. The framework was tested in the Guangdong- Hong Kong- Macao Greater Bay Area (GBA) in the period of 2000 to 2015, which can be implemented by using InVEST model, K-means clustering algorithm and correlation analysis method. The results show that 4 different ES bundles had been identified, which exhibits the spatial distribution of Bundle 1 to Bundle 4 had an extensive trend from central regions to fringe regions in the GBA. Partial correlation analysis and spearman correlation analysis were selected to quantify the trade-off and synergies relationship of ESs for each ES bundle. Meanwhile, the trade-offs and synergies relationship of ESs among each bundle was compared with the total areas of GBA, which exhibits a proportion of conspicuous differences. It indicated the framework could distinguish the spatiotemporal heterogeneity on the trade-offs and synergies relationship of ESs. A favorable application on the GBA underscored the interrelationship of multiple ESs should consider a spatiotemporal variation of the stability and ability to deliver multiple ESs from a social-ecological system. The framework for understanding the interaction relationship presented here offers a feasible workflow to evaluate trade-off strategies and policies of ecosystem management.

The dark side of the Common Agricultural Policy

The dark side of the Common Agricultural Policy

Real-time control for multi-parametric data fusion and dynamic offset optimization in sensor-based variable rate nitrogen application

Real-time sensor systems for variable rate nitrogen (N) application (VRNA) are an established technology nowadays but they have some shortcomings in terms of their capability to consider multiple parameters relevant for plant growth. Further, the abundantly lacking section control in centrifugal spreaders limits the accuracy of a sensor-based VRNA, especially in combination with the temporal and spatial offsets between sensing and fertilizer placement. Fuzzy inference systems were incorporated into a real-time control to numerically fuse the crop N uptake sensed by a real-time sensor system, as well as mapped soil electrical conductivity (ECa) data for the calculation of site-specific N dose rates (DR). A distinction of two subsections within the working width of a sensor-spreader system was made based on the ECa data. Further, by implementing a generic model, the control system agronomically optimized the rate control of a centrifugal spreader in order to compensate positional lags and technical latencies and minimize the spatial offset between DR determination and application in a dynamic manner. With field tests at different driving speed scenarios going partly beyond the usual operation conditions, the real-time control was verified. The differentiation of the sections has resulted in slight DR differences, whereas the control system has shown a high consistency in calculating the DRs and sending commands to the spreader in a coordinated manner. The level of spatial concordance between DR determination and application had a highly stochastic character. However, the deviation was never beyond 1.5 m and the percentage of deviations beyond 1 m reached a maximum of 2.3% among the different recorded datasets, which can be considered as a sufficient performance for practical needs.

Novel "late potential map" algorithm: Abnormal potentials and scar channels detection for ventricular tachycardia ablation.

Automated systems for substrate mapping in the context of ventricular tachycardia (VT) ablation may annotate far-field rather than near-field signals, rendering the resulting maps hard to interpret. Additionally, quantitative assessment of local conduction velocity (LCV) remains an unmet need in clinical practice. We evaluate whether a new late potential map (LPM) algorithm can provide an automatic and reliable annotation and localized bipolar voltage measurement of ventricular electrograms (EGMs) and if LCV analysis allows recognizing intrascar conduction corridors acting as VT isthmuses. In 16 patients referred for scar-related VT ablation, 8 VT activation maps and 29 high-resolution substrate maps from different activation wavefronts were obtained. In offline analysis, the LPM algorithm was compared to manually annotated substrate maps. Locations of the VT isthmuses were compared with the corresponding substrate maps in regard to LCV. The LPM algorithm had an overall/local abnormal ventricular activity (LAVA) annotation accuracy of 94.5%/81.1%, which compares to 83.7%/23.9% for the previous wavefront algorithm. The resultant maps presented a spatial concordance of 88.1% in delineating regions displaying LAVA. LAVA median localized bipolar voltage was 0.22 mV, but voltage amplitude assessment had modest accuracy in distinguishing LAVA from other abnormal EGMs (area under the curve: 0.676; p < .001). LCV analysis in high-density substrate maps identified a median of two intrascar conduction corridors per patient (interquartile range: 2-3), including the one acting as VT isthmus in all cases. The new LPM algorithm and LCV analysis may enhance substrate characterization in scar-related VT.

Small but visible: Predicting rare bryophyte distribution and richness patterns using remote sensing-based ensembles of small models.

In Canadian boreal forests, bryophytes represent an essential component of biodiversity and play a significant role in ecosystem functioning. Despite their ecological importance and sensitivity to disturbances, bryophytes are overlooked in conservation strategies due to knowledge gaps on their distribution, which is known as the Wallacean shortfall. Rare species deserve priority attention in conservation as they are at a high risk of extinction. This study aims to elaborate predictive models of rare bryophyte species in Canadian boreal forests using remote sensing-derived predictors in an Ensemble of Small Models (ESMs) framework. We hypothesize that high ESMs-based prediction accuracy can be achieved for rare bryophyte species despite their low number of occurrences. We also assess if there is a spatial correspondence between rare and overall bryophyte richness patterns. The study area is located in western Quebec and covers 72,292 km2. We selected 52 bryophyte species with <30 occurrences from a presence-only database (214 species, 389 plots in total). ESMs were built from Random Forest and Maxent techniques using remote sensing-derived predictors related to topography and vegetation. Lee’s L statistic was used to assess and map the spatial relationship between rare and overall bryophyte richness patterns. ESMs yielded poor to excellent prediction accuracy (AUC > 0.5) for 73% of the modeled species, with AUC values > 0.8 for 19 species, which confirmed our hypothesis. In fact, ESMs provided better predictions for the rarest bryophytes. Likewise, our study revealed a spatial concordance between rare and overall bryophyte richness patterns in different regions of the study area, which have important implications for conservation planning. This study demonstrates the potential of remote sensing for assessing and making predictions on inconspicuous and rare species across the landscape and lays the basis for the eventual inclusion of bryophytes into sustainable development planning.

The correspondence between morphometric MRI and metabolic profile in Rasmussen’s encephalitis

Volumetric magnetic resonance imaging (MRI) atrophy is a hallmark of Rasmussen’s encephalitis (RE). Here, we aim to investigate voxel-wise gray matter (GM) atrophy in RE, and its associations with glucose hypometabolism and neurotransmitter distribution utilizing MRI and PET data. In this study, fifteen RE patients and fourteen MRI normal subjects were included in this study. Voxel-wise GM volume and glucose metabolic uptake were evaluated using structural MRI and FDG-PET images, respectively. Spatial Spearman’s correlation was performed between GM atrophy of RE with FDG uptake alterations, and neurotransmitter distributions provided in the JuSpace toolbox. Compared with the control group, RE patients displayed extensive GM volume loss not only in the ipsilateral hemisphere, but also in the frontal lobe, basal ganglia, and cerebellum in the contralateral hemisphere. Within the RE group, the insular and temporal cortices exhibited significantly more GM atrophy on the ipsilesional than the contralesional side. FDG-PET data revealed significant hypometabolism in areas surrounding the insular cortices in the ipsilesional hemisphere. RE-related GM volumetric atrophy was spatially correlated with hypomebolism in FDG uptake, and with spatial distribution of the dopaminergic and serotonergic neurotransmitter systems. The spatial concordance of morphological changes with metabolic abnormalities suggest FDG-PET offers potential value for RE diagnosis. The GM alterations associated with neurotransmitter distribution map could provide novel insight in understanding the neuropathological mechanisms and clinical feature of RE.