Site Of Origin Research Articles

Cross-examining the influence of upwelling and seaweed quality on herbivores’ feeding behavior and growth

At the regional scale, upwelling conditions are known to influence ecosystems and communities and their primary and secondary productivity. However, the influence of upwelling on local herbivore-algae interactions is less well understood. We address this question by cross-examining herbivores and seaweeds from sites associated with upwelling and downwelling conditions along the Humboldt Current System. Specifically, we quantified the feeding and benefits attained by the black sea urchin (Tetrapygus niger) and the black sea snail (Tegula atra) while consuming a widespread kelp species (Lessonia spicata). We hypothesized that food quality drives herbivores' preference, consumption, and growth rates, regardless of the origin or “prior” conditions of the consumers. Laboratory trials measured algal consumption rates with (preference) and without a choice, and consumer's growth rates, to assess the influence of food quality (algae from upwelling vs downwelling sites) and the site of origin of the consumers. Our results showed that algal quality was a prevailing factor for both herbivores: they chose, consumed more, and grew faster on high quality (upwelling) algae. By comparison, the origin of the consumer was only significant for sea snails: those coming from an upwelling site, consumed significantly more and grew faster than those from downwelling. The bulk of our results provided strong support to our hypothesis and suggest that the high nutritional quality of algae associated with upwelling centers has a strong influence on consumers' preferences, consumption, and performance (growth). The fact that origin was found to be relevant for one of the herbivores suggests that the conditions in which species grow may dictate some of their efficiency as consumers.

GAD2 is a highly specific marker for neuroendocrine neoplasms of the pancreas

Abstract Introduction/Objective Glutamate decarboxylase 2 (GAD2) is the most important inhibitory neurotransmitter and plays a role in insulin-producing β-cells of pancreatic islets. The limitation of GAD2 expression to normal brain and pancreatic islet cells makes GAD2 a potential immunohistochemical diagnostic marker. Methods/Case Report To evaluate the diagnostic utility of GAD2 immunohistochemistry (IHC), a tissue microarray containing 19,202 samples from 152 different tumor entities and 608 samples of 76 different normal tissue types was analyzed. Data on progesterone receptor (PR) expression were available on 15,232 tumors from a previous study. Results (if a Case Study enter NA) GAD2 positivity occurred in 20 of 152 tumor categories including 5 tumor categories with at least one strongly positive case. GAD2 positivity was most frequent in neuroendocrine carcinomas (58.3%) and neuroendocrine tumors (63.2%) of the pancreas, followed by granular cell tumors (37.0%) and neuroendocrine tumors of the lung (11.1%). GAD2 in <10% of cases occurred in 16 other tumor entities including paraganglioma, medullary thyroid carcinoma, and small cell carcinoma of the urinary bladder. In a cohort of 95 pancreatic and 380 extra-pancreatic neuroendocrine neoplasms, GAD2 had a sensitivity of 64.2% and a specificity 96.3% for pancreatic tumor origin while PR had a sensitivity of 56.8% and a specificity of 92.6%. Conclusion GAD2 IHC is a highly useful diagnostic tool for the identification of pancreatic origin in case of neuroendocrine neoplasms with unknown site of origin. The particular strength of GAD2 is its high specificity for pancreatic origin. For the distinction of a pancreatic tumor origin, both sensitivity and specificity is higher for GAD2 than for PR. The combination of PR and GAD2 further increases sensitivity and specificity.

Exploration and growth characteristics of allopolyploids derived from interspecific hybridization between Neopyropia yezoensis and Neopyropia tenera (Bangiales, Rhodophyta) in natural populations of eastern Japan

We investigated the distribution of allopolyploids of the red algal genus Neopyropia (referred to as nori) in natural populations of eastern Japan and compared the growth characteristics of allopolyploids and ancestral species under laboratory culture. To detect hybrids between Neopyropia yezoensis and Neopyropia tenera, 99 samples collected from 7 localities were examined by sequence analysis of the chloroplast RUBISCO spacer region and DNA marker analyses of two nuclear genes. The results indicated that 20 samples were hybrids derived from interspecific hybridization between the two species. Using 5 conchocelis strains among the hybrids, the blades that developed from both conchospores and archeospores were obtained under laboratory culture and were examined by nuclear DNA marker analyses to confirm allopolyploidy. As a result, the five strains were confirmed as allopolyploids derived from interspecific hybridization between N. yezoensis as the maternal strain and N. tenera as the paternal strain. Furthermore, from two of the five strains, the allopolyploid strains TUYTA-7 and TUYTA-8 were established via self-fertilization of the blade from an archeospore, and the blade growth and photosynthetic pigments of the two strains were compared with those of the strain UM-T55 of the ancestral species N. tenera collected from the same origin site as the two strains. In the allopolyploid strains, the TUYTA-8 blades exhibited superior characteristics, such as a long and linear shape, rapid elongation, low fertility and high pigment content. These results imply the importance of exploring and isolating more allopolyploid strains in bladed Bangiales. Moreover, it is possible that polyploid breeding due to interspecific hybridization in the bladed Bangiales will become more popular as a practical method for developing new cultivars of nori.

Benign Tumor Publication in One Year (2022): A Cross-Sectional Study

Introduction A benign tumor is a form of abnormal cell proliferation that remains confined to its site of origin, grows slowly, does not spread to distant body parts, nor does it invade the surrounding local structures. In this study, we aim to evaluate and list the scientific publications regarding benign tumors in the year 2022. Methods A cross-sectional study was conducted, including the published papers on benign tumors in the year 2022. The data were collected online from the Google Scholar search engine and recorded in Microsoft Excel 2010. The extracted data were calculated and thoroughly re-evaluated, then presented as frequencies and percentages. Results A total of 17,007 medical studies were included in this report, with the brain having 3,450 (20.3%) studies, making it the organ with the most studies, whereas the hypopharyngeal portion of the throat had only one study and is, hence, the least studied one. Conclusion There is limited reporting and data available on benign tumors, and they are very scattered, leading to either a lack of or a misunderstanding of the burden they pose.

Looking back over the shoulder: New insights on the unique scapular anatomy of the tapir (Perissodactyla: Tapiridae).

The musculoskeletal anatomy of the shoulder of many ungulates has been inferred from veterinary model taxa, with uniformity in muscle arrangements and attachment sites often assumed. In this study, I investigated the muscular and osteological anatomy of tapirs and their relatives (Perissodactyla: Tapiroidea), using a combination of gross dissection and digital imaging (photography and laser surface scanning). Dissections of three modern tapir species revealed that the m. infraspinatus originates from both supraspinous and infraspinous fossae for all species, lying on both sides of the distal scapular spine. The epimysial border between the m. supraspinatus and m. infraspinatus origin sites are marked in all species by an ossified ridge, sometimes extending the length of the scapular spine. This "supraspinous ridge" is clearly visible on the scapular surface of both modern and extinct Tapirus scapulae; however, the ridge does not appear present in any non-Tapirus tapiroids examined (e.g., Helaletes, Nexuotapirus), nor in other perissodactyls or artiodactyls. Moreover, the ridge exhibits a clearly distinct morphology in Tapirus indicus compared to all other Tapirus species examined. Combined, these findings indicate that the presence and position of the "supraspinous ridge" may represent a robust phylogenetic character for reconstructing relationships within tapiroids. Unfortunately, any functional locomotor outcomes or benefits of the m. infraspinatus straddling the scapular spine remains elusive. This study represents a firm reminder for anatomists, veterinarians, and paleontologists to (where possible) look beyond veterinary model systems when inferring musculoskeletal form or function in non-model organisms.

NIMG-72. CONTRALATERAL PREDOMINANT BLOOD SUPPLY OF FALX AND PARASAGITTAL MENINGIOMA BASED ON ANGIOGRAPHIC ANALYSIS

Abstract INTRODUCTION Preoperative prediction of blood supply in meningiomas is important to avoid unexpected intraoperative bleeding. Herein, we investigated the relationship between the location of meningioma and the dominant side of feeding arteries. METHOD: Between January 2018 and December 2020, a total of 101 consecutive patients underwent craniotomy for meningioma at our hospital. Among them, 43 cases in which the lesions were clearly localized on the right or left sides received preoperative angiography including bilateral common or external carotid artery (ECA) imaging. A region of interest (ROI) was set at the most stained area in (X) meningioma and (Y) main trunk of the ECA. In each affected side (AS) and healthy side (HS), the ratio of ROI (X) value to ROI (Y) value; tumor / vessel ratio (TVR = 0 ~ 1) was calculated. Multivariate analysis was performed to compare TVR between AS and HS, and to analyze factors associated with TVR, such as site of origin (convexity, skull base and relating falx), age, gender, WHO grading, and tumor diameter. RESULTS TVR was significantly higher in AS (0.60; 0.41 - 0.91) than HS (0.47; 0.39 - 0.99) (p=0.0003). HS was superior to AS in 10 cases, all of which were falx (6 of 9 cases) or parasagittal (4 of 10 cases) meningioma. 53% of falx and parasagittal meningiomas showed HS predominant TVR. Concerning factors associated with the TVR of HS predominance, falx origin was extracted as an independent factor (p< 0.0001). DISCUSSION The vessels crossing in the falx, which consist with particular anatomical structure, fusing the meningeal layers in each side of dura mater would contribute to this finding. CONCLUSION Falx and parasagittal meningiomas should consider the predominant influx of tumor feeding vessels from HS.

NIMG-81. ASSOCIATION OF THE ORIGIN OF CRANIOPHARYNGIOMA WITH OPTIC TRACT EDEMA

Abstract OBJECTIVE Optic tract edema (OTE) is a useful finding in the diagnosis of craniopharyngioma (CP). However, the pathogenesis of OTE is not fully understood. In this study, we investigated the presence of OTE depending on the site of origin of CP. METHODS We reviewed 48 patients with CP who underwent surgical treatment at Juntendo University Hospital between March 2010 and February 2023 and investigated their size, location, presence of OTE, pathological subtypes, and genetic abnormalities. Tumors were classified into four groups based on their origin: retrochiasmatic (RC) type, prechiasmatic (PC) type, intrasellar (IS) type, and intra-third-ventricle (ITV) type. RESULTS Forty-eight cases were included in this study. The number of cases of RC, PC, IS, and ITV types were 29, 8, 3, and 8, respectively. OTE was shown in 21 cases. Among them, RC type was the most common location (18 cases, 86%) with significant differences. The cystic component of the tumor was in contact with the optic tract in 15 cases, which was more common than the solid component. DISCUSSION Possible causes of OTE include cytotoxic edema associated with inflammation, angiogenic edema due to leakage of serum components from the tumor, leakage of fluid components from the cyst, and enlargement of the Virchow-Robin space in the optic disc. In this study, many of the cases with OTE have cystic components in contact with the optic tract, suggesting leakage of fluid components from the cyst as the pathogenesis of OTE. The presence of OTE can be a new factor to determine the surgical approach since CP with OTE is thought to extend posteriorly to the optic chiasm. CONCLUSIONS OTE is often associated with RC type CP and is thought to be caused by leakage of fluid from the cyst.

EPCO-03. A COMPREHENSIVE SINGLE-CELL ATLAS OF SCHWANNOMA REVEALS CONSERVED CELLULAR STATES ACROSS DIFFERENT GENETIC BACKGROUNDS AND ANATOMIC LOCATIONS

Abstract BACKGROUND Despite being associated with molecular alterations in the NF2 gene, there is limited understanding of the gene expression programs that govern the behavior of schwannomas both in sporadic cases as well as in patients with schwannoma predisposition syndromes, and also with respect to their anatomic location. METHODS We characterized the transcriptional heterogeneity of schwannomas across different genetic backgrounds and anatomic locations at the single-cell level. Tumor samples from patients undergoing resection for symptomatic schwannoma were dissociated and single cells were processed for full-transcript whole transcriptome profiling via Smart-seq2. Our cohort of 22 schwannomas, includes 5 tumors from schwannomatosis patients, 11 tumors from neurofibromatosis type 2 patients, and 6 sporadic tumors – 3 of which had grown after radiation treatment. Anatomically, 12 tumors were excised from cranial nerves (11 vestibular, 1 accessory) and 10 from spinal and other peripheral nerves. RESULTS We profiled 11,373 cells, including 4725 neoplastic cells, 2425 fibroblasts, 1314 T cells, 1258 endothelial cells, 969 myeloid cells, 503 pericytes and 240 Schwann cells. Copy number alteration analyses reveal evidence of intratumoral polyclonality (supporting the hypothesis of multiple sites of origin for a tumor). Using non-negative matrix factorization, we identify 6 distinct transcriptional metaprograms, with gene signatures related to stress, myelin production, antigen presentation, interferon signaling, glycolysis and extracellular matrix. After comparison with a pan-cancer gene expression dataset, we note unique interferon and antigen presentation metaprograms in schwannoma, with the latter being mainly characterized by expression of MHC Class II genes. Overall, we observe conserved expression of these metaprograms across anatomic locations and genetic backgrounds, with the exception of decreased interferon signaling for vestibular tumors. CONCLUSION We provide a comprehensive single-cell characterization of schwannoma spanning diverse genetic and anatomic backgrounds. We describe unique transcriptional metaprograms for antigen presentation and interferon signaling, which might underlie mechanisms for immune evasion.

Experimental Approach for Clarifying Initiation and Growth Behaviors of Internal Fatigue Cracks Using Synchrotron Radiation Multiscale X-ray Computed Tomography

Abstract The very high cycle fatigue (VHCF) phenomenon has been recognized and extensively studied in the past quarter century. One of the most peculiar and noticeable characteristics of VHCF is the transition of the origin site from the surface to the interior of the material in long-life regimes over 107 cycles. In particular, in high-strength metals, a tiny site can become an origin of internal fatigue cracks, such as nonmetallic inclusions of several micrometers to several tens of micrometers in high-strength steels and crystal grains of several tens of micrometers in titanium alloys. However, such small cracks are difficult to detect using conventional nondestructive approaches, such as industrial X-ray computed tomography (CT) or ultrasonic CT. Given this background, we have attempted to use a synchrotron radiation multiscale X-ray CT provided by SPring-8 in Japan. This system comprises a projection CT (micro-CT) with a spatial resolution of approximately 1 μm and a phase-contrast imaging CT (nano-CT) with a spatial resolution of approximately 200 nm or higher. The present study introduces our experimental approach to clarify internal fatigue crack behaviors using the multiscale X-ray CT with in situ fatigue testing. First, the principle of material selection focusing on the VHCF study is explained with the details of the materials used: (α+β) type Ti-6Al-4V, β type Ti-22V-4Al, and 17-4 precipitation-hardened martensite stainless steel. Afterward, the outline and primary performance of the multiscale X-ray CT are described. Subsequently, important points in conducting accurate in situ fatigue tests are discussed from the viewpoints of the development policies of the testing system and preparation of the special thin specimen for CT imaging. Finally, the multiscale X-ray CT is conducted for the above materials, and the initiation and growth behaviors of the internal fatigue cracks are compared and discussed for an in-depth understanding of the VHCF phenomenon.

Association of ventricular tachycardia morphology induced on electrophysiology study after myocardial infarction: long-term survival and ventricular tachyarrhythmia recurrence

Abstract Background Electrophysiology study (EPS) presents a valuable risk stratification tool to facilitate the implantation of implantable cardioverter-defibrillators (ICDs) to prevent sudden cardiac death from ventricular tachyarrhythmia early after myocardial infarction. Purpose To investigate long-term survival of patients with inducible ventricular tachycardia (VT) at electrophysiology study (EPS) early after ST elevation myocardial infarction (MI) and possible association with site of origin of the induced VT. Methods Consecutive patients with LVEF ≤40% on day 3–5 after MI who underwent EPS were prospectively recruited. Positive EPS was defined as sustained monomorphic VT cycle length ≥200ms for >10 seconds, or shorter duration if hemodynamic compromise occurred. The primary outcome was time to death from any cause. The secondary outcome was time to the composite endpoint of first activation of ICD for ventricular tachyarrhythmia or death. Results A total of 126 patients with inducible VT on EPS early after MI were included with median follow up 6.7 years. 54% had LBBB and 46% had RBBB morphologies during induced VT. The distributions of age, sex, left ventricle ejection fraction, cardiovascular risk factors, infarct artery and EPS characteristics did not differ significantly by induced VT morphology. The estimated risk of death was independently associated with RBBB morphology of VT induced at EPS (adjusted HR 3.2, 95%CI 1.0-10.0, p=0.044). The estimated risk of the composite end-point of spontaneous ventricular tachyarrhythmia recurrence or death was also independently associated with RBBB morphology of VT induced at EPS (HR 1.8, 95%CI 1.0-3.2, p=0.043). Conclusion There is an increased risk of death and spontaneous ventricular tachyarrhythmia recurrence at median follow up of 6.7 years, associated with RBBB morphology of VT (likely origin from left ventricle) induced at EPS early after MI, in those with LVEF <40%. This study is the first to characterise the association between site of origin of VT induced at EPS after myocardial infarction, indicated by RBBB or LBBB morphology, and overall survival as well as activation free survival. The results could help to identify a group of patients that could benefit from closer monitoring post MI and more intense preventative management to improve long-term outcomes.

Abstract 15939: Site of Origin Associated With Differences in Day-to-Day Variability of Premature Ventricular Contractions

Background Premature ventricular contractions (PVC) from the ventricular outflow tracts are well characterized, but there is limited literature to describe how other sites of origin (SOO) correlate with clinical and electrophysiologic characteristics. Methods We analyzed single lead ambulatory loop monitors (Zio, iRhythm, San Francisco, CA) from 1/2017-3/2020 (n=581) at a single institution. All included subjects had a PVC burden >1% and monitoring period of >72 hours. Twelve-lead ECG of the PVC for each subject was reviewed by an electrophysiologist to identify the SOO. Demographic information, clinical presentation, and cardiac testing results were collected from the electronic medical record. Those without a PVC captured on ECG or with atrial fibrillation or flutter were excluded. Analysis was performed via calculation of odds ratios for presence of dichotomous characteristics and two-tailed t-tests for comparison of means, stratified by outflow tract (OT) versus non-OT SOO and perivalvular (PV) versus non-PV SOO. Results Of 39 subjects who met criteria for inclusion, stratified by SOO (analysis 1: OT (n=18), non-OT (n=21), analysis 2: PV (n=30), non-PV (n=9)), there were no significant differences in the odds of developing certain symptoms or exhibiting certain PVC characteristics. PVCs from OT vs. non-OT and PV vs. non-PV locations had similar burden and numbers of single PVCs, couplets, and triplets. Odds of reporting symptoms were higher with OT than non-OT PVCs (OR 1.49, 95% CI 0.86 - 2.58) and with PV than non-PV PVCs (OR 1.70, 95% CI 0.85 - 3.41). PVC-Native QRS Duration index was no different between SOO groups. Day-to-day variability of PVC burden was higher in OT vs. non-OT SOO (p=0.08), with no difference in PV vs. non-PV SOO (p=0.90). Odds of RV dysfunction were higher in PV vs. non-PV SOO (OR 8, 95% CI 1.54 - 41.64). Coupling interval was longer in non-PV PVCs vs. PV PVCs (n=29, p=0.02). Discussion Electrophysiologic characteristics of PVCs from different sites of origin were similar, suggesting common mechanisms. OT PVCs exhibited more day-to-day variability, emphasizing the need for extended monitoring to characterize true PVC burden. Exploratory analysis by SOO suggests more frequent symptoms with OT PVCs, and RV dysfunction with non-PV SOO.

Abstract 16985: Spatial Accuracy of Non-Invasive Activation Mapping Modalities for Complex Ventricular Arrhythmias: A Direct Comparison of Electromechanical Wave Imaging (EWI) Using High Frame Rate Transthoracic Echocardiography and Electrocardiographic Imaging (ECGi) With Cardiac CT

Background: Non-invasive identification of the site of origin (SOO) of ventricular arrhythmias is vital in informing ablation strategy. ECGi is an established method to generate 3D activation maps with a multielectrode vest combined with cardiac CT. EWI is an emerging echocardiography based modality that provides a low cost & non-ionizing mapping alternative. Hypothesis: EWI more precisely localises SOO of Complex Ventricular Ectopy (VEs) & intramural location than commercial ECGi. Aim: Compare spatial accuracy of EWI and ECGi to estimate SOO and validate against contact mapping. Methods: VE-ablation patients underwent preprocedural EWI & ECGi to estimate SOO on the AHA segment-model. A commercial ECGi system with cardiac CT was used for reconstruction of epicardial VE activation maps. EWI was performed using a research ultrasound acquiring B-mode and high frame rate (2000fps) images with simultaneous ECG. Local electromechanical activation was defined as time-point of the downward zero-crossing on the incremental axial strain curve (250 strain curves/view) and displayed on 3D rendered maps. The site of earliest activation & successful VE ablation was defined as ground truth for VE SOO. Results: 10 patients were enrolled: 50% male, age 40.8 +/- 18.1 years, LV EF 41+/-15%, 50% with scar on MRI. CT ECGi correctly identified the VE AHA segment in 8/10 (80%) cases (misclassified 2 papillary muscle (PM) VEs) but did not afford transmural localization. After excluding 1 patient with insufficient VE’s for EWI, EWI correctly identified the VE-SOO segment in 8/9 (88%) cases locating 2 subepicardial, 2 septal intramural & 3 VEs at the base or intramural segment adjacent to a PM. It misclassified 1 PM VE. Conclusion Both EWI & ECGI identified the VE-SOO segment in at least 80% of cases irrespective of presence of scar. EWI also correctly determined the transmural VE origin which cannot be located using commercial ECGI. This has important implications in planning ablation procedures.

Abstract 15352: Deep Learning Model-Enabled Electrocardiogram to Localize Premature Ventricular Contractions in Patients Referred for Catheter Ablation

Introduction: Accurate pre-procedure localization of the premature ventricular contractions (PVCs) is critical in preparing for the ablation. So far, no tools exist for artificial intelligence guided PVC-localization. Hypothesis: Trained deep learning model will be able to predict the site of origin (SOO) of PVCs using 12 lead electrocardiogram (ECG). Methods: We analyzed 707 ECG-ablation pairs from 2403 patients who had at least one ECG flagged for PVCs in the 6 months prior to their procedure. First, we used a cohort of 100,000 ECGs without PVCs and 10,000 ECGs with PVCs to train a convolutional neural network (CNN) to isolate the ECG segments with PVCs in them from a 12-lead ECG (Figure 1). We then trained two models, one utilizing a 10-second 12-lead ECG, and the other with just the isolated PVC beats as input. The models were trained using the Keras framework with TensorFlow (Google). Results: The mean age of the patients in the cohort was 61.2 ± 15.0 years. 66.3 percent of patients underwent left ventricle ablation, 54.6 percent had outflow ablation, and 55.3 percent had ablation of sites with leftward axis (septal location for midline and left ventricle PVCs). The model trained on 10-second ECGs yielded validation and test AUCs of 0.941 and 0.931 for outflow, 0.898 and 0.891 for ventricle, and 0.863 and 0.846 for leftward axis (Figure 1A). The model trained on isolated segments containing PVC beats yielded validation and test AUCs of 0.966 and 0.957 for outflow, 0.879 and 0.907 for ventricle, and 0.846 and 0.829 for SOO for leftward axis (Figure 1B). Conclusions: We have trained an accurate convolutional neural network that can predict SOO using the surface ECG. Further fine-tuning would be needed to refine the model and develop prediction of specific sites.

Abstract 13269: Clinical and Electrophysiological Features of New Onset Ventricular Arrythmias Following Catheter Ablation of Atrial Fibrillation

Introduction: Data on new onset ventricular arrhythmias (VAs) following catheter ablation of atrial fibrillation (AF) is sparse. Hypothesis: We aimed to assess the incidence of new onset VA post AF RFA. Methods: We conducted a retrospective study of all patients at our institution that underwent AF ablation who also developed symptomatic high burden premature ventricular complexes (PVCs) requiring catheter ablation within 1 year of the index AF ablation procedure. All patients underwent post AF ablation monitoring with either 48 hr Holter monitors or implantable cardiac monitors. New onset VA was defined as symptomatic new onset PVC with >5% burden. Data on PVC morphology and successful ablation sites was analyzed. Results: Out of 175 patients that underwent AF ablation during the study period, 2.8 % (n=5) patients developed new onset high burden PVCs requiring catheter ablation therapy within 1 year of AF ablation. Mean age was 68.6 + 11 years and all patients were male. Mean baseline LVEF was 56 + 9.6% and mean PVC burden was 10.3 + 8.8 %. A total of 9 PVCs were mapped in 5 patients. The number of VA morphology was 1 in 2 (40%) patients, 2 in 2 (40%) and 3 in 1 (20%) patient. Site of origin for the PVCs was in the left ventricle in all patients, with majority (55%) localizing to the LV outflow tract and summit region (table). Average time from AF RFA to PVC ablation was 4 + 2.9 months. PVC ablation was successful in all patients except one where ablation was deferred due to proximity to the conduction system. Conclusions: New onset VAs following catheter ablation of AF tend to localize to the LV outflow tract and areas of bipolar voltage abnormality. Potential mechanisms of new onset PVCs could include altered sympathetic tone due to ablation of cardiac ganglia, unmasking of PVCs due to regularization of ventricular rate and withdrawal of anti-arrhythmic medications. Further prospective studies are needed to understand true incidence of new onset VAs following AF ablation.

Cold wintertime air masses over Europe: where do they come from and how do they form?

Abstract. Despite the general warming trend, wintertime cold-air outbreaks in Europe have remained nearly as extreme and as common as decades ago. In this study, we identify six principal 850 hPa cold anomaly types over Europe in 1979–2020 using self-organizing maps (SOMs). Based on extensive analysis of atmospheric large-scale circulation patterns combined with nearly 2 million kinematic backward trajectories, we show the origins and contributions of various physical processes to the formation of cold wintertime 850 hPa air masses. The location of the cold anomaly region is closely tied to the location of blocking; if the block is located farther to the east, the cold anomaly is also displaced eastwards. Considering air mass evolution along the trajectories, the air parcels are typically initially (5–10 d before) colder than at their arrival in Europe, but initially warmer air parcels also sometimes lead to cold anomalies over Europe. Most commonly the effect of adiabatic warming on the temperature anomalies is overcompensated for by advection from regions that are climatologically colder than the target region, supported by diabatic cooling along the pathway. However, there are regional differences: cold anomalies over western Europe and southeastern Europe are dominantly caused by advection and over eastern Europe by both advective and diabatic processes. The decadal-scale warming in the site of air mass origin has been partly compensated for by enhanced diabatic (radiative) cooling along the pathway to Europe. There have also been decadal changes in large-scale circulation patterns and air mass origin. Our results suggest that understanding future changes in cold extremes will require in-depth analyses of both large-scale circulation and the physical (adiabatic and diabatic) processes.

Coupled Eulerian Wall Film–Discrete Phase model for predicting respiratory droplet generation during a coughing event

Infectious respiratory diseases have long been a serious public health issue, with airborne transmission via close person-to-person contact being the main infection route. Coughing episodes are an eruptive source of virus-laden droplets that increase the infection risk of susceptible individuals. In this study, the droplet generation process during a coughing event was reproduced using the Eulerian wall film (EWF) model, and the absorption/expulsion of droplets was tracked using the discrete phase model (DPM). A realistic numerical model that included the oral cavity with teeth features and the respiratory system from the throat to the first bifurcation was developed. A coughing flow profile simulated the flow patterns of a single coughing episode. The EWF and DPM models were coupled to predict the droplet formation, generation, absorption, and exhalation processes. The results showed that a large droplet number concentration was generated at the beginning of the coughing event, with the peak concentration coinciding with the peak cough rate. Analysis of the droplet site of origin showed that large amounts of droplets were generated in the oral cavity and teeth surface, followed by the caudal region of the respiratory system. The size of the expelled droplets was 0.25–24 μm, with the peak concentration at 4–8 μm. This study significantly contributes to the realm on the site of origin and localized number concentration of droplets after a coughing episode. It can facilitate studies on infection risk assessment, droplet dispersion, and droplet generation mechanisms from other sneezing or phonation activities.

A decade in focus: mixed germ cell tumors with choriocarcinoma components

Introduction: This 10-year registry review aimed to investigate the clinical behaviour and outcomes of mixed germ cell tumours with choriocarcinoma components, a rare and aggressive subtype of testicular cancer, in Saudi Arabia. The study explores the demographic characteristics of affected patients, tumour profiles, and the mortality rate associated with this malignancy. Methods: Utilizing data from the Saudi Cancer Registry, the authors identified 33 cases of mixed germ cell tumours with choriocarcinoma components among 1001 testicular cancer cases recorded between 2008 and 2017. Demographic information, including age, marital status, region of residency, year of diagnosis, and 10-year survival status, were collected. Tumour factors, such as the basis of diagnosis, origin site, behaviour, grade, extension, and laterality, were also analyzed. Results: The majority of cases (78.8%) occurred in the young age group (18–45 years), and most tumours (97%) originated in normally descended testes. Grade IV (undifferentiated anaplastic) tumours and distant metastasis were present in 45.5% of patients. All cases exhibited malignant tumour behaviour. The overall mortality rate was 15%, with a mean time from diagnosis to death of 7.72 months (range: 0.5–21.5 months). Conclusion: Mixed germ cell tumours with choriocarcinoma components are rare and tend to affect younger populations. These tumours demonstrate aggressive clinical behaviour, with a significant proportion presenting with high-grade lesions and metastasis at diagnosis. The observed mortality rate underscores the poor prognosis associated with this malignancy. Our study provides essential insights into the clinical characteristics of this rare tumour subtype in the Saudi Arabian population, emphasizing the need for further research to identify prognostic factors and optimize management strategies for affected patients.

Aging varies greatly within a single genus: A demographic study of Rhododendron spp. in botanic gardens.

There is mounting evidence that age matters in plant demography, but also indications that relationships between age and demographic rates may vary significantly among species. Age-based plant demographic data, however, are time-consuming to collect and still lacking for most species, and little is known about general patterns across species or what may drive differences. We used individual birth and death records for 12 Rhododendron species from botanic gardens and conducted Bayesian survival trajectory analyses to assess how mortality changed with age. We calculated the demographic measures of aging rate, life-span equality, and life expectancy for each species, and assessed their relationships with the climatic conditions at species' sites of ancestral origin and with taxonomic group (subgenus). We found substantial among-species variation in survival trajectories, with mortality increasing, decreasing, or remaining constant with advancing age. Moreover, we found no relationships between demographic measures and ancestral climatic conditions but there were statistically significant differences among taxonomic groups in the rate of change in mortality with age (aging rate). We conclude that demographic consequences of aging can differ qualitatively, even among species in the same genus. In addition, taxonomic trends in aging rates indicate they may be genetically determined, though evolutionary drivers are still unclear. Furthermore, we suggest there is untapped potential in using botanic garden records in future studies on plant life history.

Accuracy of an AI prediction platform in predicting tumor origin: A real-world study.

74 Background: Only four cancers are covered by screening programs. The remaining cancers are diagnosed after a point-of-care presentation to a primavry care physician (PCP). Patients with these cancers typically present with a combination of vague and non-specific symptoms, lacking specificity to a particular tumor type. The difficulties in interpreting these symptoms by PCPs leads to increased diagnostic intervals and the use of invasive diagnostic modalities with unnecessary radiation exposure. Localizing the cancer origin is critical to reduce time to diagnosis in order to improve earlier diagnosis and survival in these cancer types. C the Signs is a clinical platform integrated with electronic health records (EHR) that uses artificial intelligence to help identify patients at risk of cancer. Used by PCPs during a point-of-care assessment, C the Signs analyses the symptoms the patient presents with, alongside clinical data in the EHR, to identify current cancer risk, predict the tumor site of origin, and recommend the most effective diagnostic or referral pathway. The aim of this study is to evaluate the accuracy of C the Signs in predicting cancer origin for patients in a real-world setting. Methods: An observational study was conducted between 1st January 2021 and 31st October 2022 in the National Health Service in England utilizing all patients who were risk-assessed with the C the Signs EHR integrated platform. There was no pre-selection criteria for the patient population assessed. All patients were followed up with for 6 months post-risk assessment to determine if they had a cancer diagnosis. Analysis was performed on the patients who were identified at risk of cancer by the C the Signs platform and subsequently diagnosed with cancer, to establish the cancer origin accuracy. Results: 111,421 patients were risk-assessed by C the Signs, of which 7,360 were diagnosed with cancer. Of the patients diagnosed with cancer, 7,257 patients were identified at risk of cancer by C the Signs (98.67%). The platform predicted cancer origin accurately in 93.2% of patients. The platform was most accurate in predicting cancer origin for brain and CNS, breast, lung, gynecological, head & neck, bowel, skin, and prostate cancers. Conclusions: This study demonstrates how a cancer prediction platform such as C the Signs can be used to accurately detect tumor origin in patients with vague symptoms and facilitate targeted investigations appropriate to the tumor type. Further research is required to identify which cancers can be most accurately detected taking a computational approach.

Identifying Origin of Nonpulmonary VeinTriggers Using 2 Stationary LinearDecapolar Catheters: A Novel Algorithm.

Targeting nonpulmonary vein triggers (NPVTs) of atrial fibrillation (AF) after pulmonary vein isolation can be challenging. NPVTs are often single ectopic beats with a surface P-wave obscured by a QRS or T-wave. The goal of this study was to construct an algorithm to regionalize the site of origin of NPVTs using only intracardiac bipolar electrograms from 2 linear decapolar catheters positioned in the posterolateral right atrium (along the crista terminalis with the distal bipole pair in the superior vena cava) and in the proximal coronary sinus (CS). After pulmonary vein isolation in 42 patients with AF, pacing from 15 typical anatomic NPVT sites was conducted. For each pacing site, the electrogram activation sequence was analyzed from the CS catheter (simultaneous/chevron/inverse chevron/distal-proximal/proximal-distal) and activation time (ie, CSCTAT) between the earliest electrograms from the 2 decapolar catheters was measured referencing the earliest CS electrogram; a negative CSCTAT value indicates the crista terminalis catheter electrogram was earlier, and a positive CSCTAT value indicates the CS catheter electrogram was earlier. A regionalization algorithm with high predictive value was defined and tested in a validation cohort with AF NPVTs localized with electroanatomic mapping. In the study patient cohort (71% male; 43% with persistent AF, 52% with left atrial dilation), the algorithm grouped with high precision (positive predictive value 81%-99%, specificity 94%-100%, and sensitivity 30%-94%) the 15 distinct pacing sites into 9 clinically useful regions. Algorithm testing in a 98 patient validation cohort showed predictive accuracy of 91%. An algorithm defined by the activation sequence and timing of electrograms from 2 linear multipolar catheters provided accurate regionalization of AF NPVTs to guide focused detailed mapping.